A Solar Tale

Remember “The Long Tail”? Maybe not. Unless you were up to your eyeballs in the nuances of search engines and niche marketing around the turn of the century, you wouldn’t. The phrase originated with a Wired article by Chris Anderson, but more generally Marziah Karch describes it like this; traditionally records, books, movies, and other items were geared towards creating “hits.” Stores could only afford to carry the most popular items because they needed enough people in an area to buy their goods in order to recoup their overhead expenses. The Internet changes that. It allows people to find less popular items and subjects. It turns out that there’s profit in those “misses,” too. Amazon can sell obscure books, Netflix can rent obscure movies, and iTunes can sell obscure songs. That’s all possible because the Internet, search engines and search advertising provide easy access to these niches out on the long tail of the demand curve, allowing them to compete with the head of the curve where the big hits and brick and mortar stores reside.

What does this have to do with solar energy? Plenty as it turns out. Demand for solar has traditionally been met by large, centralized solar farms that generate many megawatts of energy per system, per day, like the big-box retail stores of yore selling blockbuster records, books and movies, the hits at the head of the solar demand curve.

These centralized solar farms are comprised of rows and rows of identically mounted flat crystalline solar modules tilted at the ideal angle for the latitude. With their economies of scale they deliver the lowest installed system costs, in the $2 per watt range according to Greentechsolar, if you ignore the typical transmission infrastructure additions and upgrades required to deliver this energy to market. String inverters are a key ingredient in delivering such favorable economics. Large strings of solar modules, devoid of shading and other sources of performance differences between modules, can be connected to a single, rather expensive string inverter. The number of solar modules per string inverter, and therefore the number of watts by which the cost of the string inverter gets divided, is large, rendering favorable dollars per watt.

Centralized solar farms also fit neatly into the existing utility-driven paradigm and business model. Energy is generated centrally, delivered over wide area networks of transmission and distribution lines to paying customer loads and then paid for and recouped by regulated returns over long time horizons. These are the big hits.

Like the big box retail stores with search advertising, though, this centralized utility-scale model is being disrupted. Land acquisition and permitting for new solar farms combined with the challenges of adding net new or even upgrading existing transmission and distribution lines is constraining big solar. At the same time the cost of crystalline solar modules and supporting electronics has plummeted, opening up the first wave of distributed solar, known more commonly as rooftop solar. Rooftops are smaller than the acres devoted to centralized solar farms, by a lot, so the fixed costs of a rooftop solar generating system – e.g., solar modules, inverters, mounting infrastructure – are divided by fewer watts. As a result, the dollars per watt for rooftop solar initially suffered by comparison, but continues to get rosier and rosier as these costs continue their precipitous decline, sitting just under $4 per watt according to the same Greentechmedia study.

Rooftop solar is more distributed than a centralized solar farm, and more varied. A single rooftop may have several different pitches and possibly even directions these pitches face. Since economics will always drive towards maximizing the number of watts installed per rooftop, these variations become more and more common. Plus, shading plays a role. Rooftops are not pristine like single-purpose solar sites. Trees, neighbor houses, nearby foothills and the like can cause seasonal shading during times of the day, emphasizing the point that a rooftop is first and foremost, a rooftop. Fortunately for the rise of distributed solar, a Module-Level Power Electronics (MLPE) market has emerged to assuage the technical ramifications. Microinverters and power optimizers are examples of MLPEs. Each optimizes a single solar module’s output, an important innovation when adjacent solar modules may perform very differently due to shading or even their orientation relative to the sun. Mating a microinverter or power optimizer with every solar module costs more in dollars per watt, but as the distributed solar market grows and gains economies of scale for MLPE manufacturers, costs are coming down rapidly as they have with solar modules, while overall system generation across varied solar modules increases.

 Many Facet Rooftop Solar

Rooftop solar is filling out the inflection point between the head of the solar demand curve and the tail, but it cannot fuel the long tail all on its own. As of the third quarter of 2014, nearly 600,000 home and business owners already generate their own solar electricity from rooftop systems. Unfortunately, only as many as 20% of rooftops are suitable to host solar generation. Plus socially, rooftop solar contributes to the electrical divide, the increasing cost of energy low-income families will face as part of the utility death spiral – i.e., the concept where falling barriers to distributed generation coupled with rising electric bills will cause consumers to defect from the grid, leaving a smaller population to pay for the costs of maintaining the electrical infrastructure. This smaller population is filled with low-income families, families without the means or often even the rooftops to participate in the benefits of rooftop solar.

What will fuel the long tail? What is at least as distributed and local as rooftop solar, more egalitarian and offers unlimited surface area to cover and generate solar energy? Infrastructure Solar! Imagine the ability to economically cover all shapes and sizes of existing infrastructure out in the wild with solar generation, like light and utility poles of all heights and diameters, traffic intersection poles and arms and supports, bus and rail stops, wind turbine towers, water towers, floating bridge barricades, the list goes on and on. Each system is small in terms of nameplate generation – a 75 kilowatt lighting system, a 4.5 kilowatt traffic intersection – but like the Long Tail of the Internet, the sum of all installed Infrastructure Solar kilowatts will eventually dwarf the centralized and rooftop kilowatts being installed today because, well, the tail is really, really long.

Solar Cells and Modules

Standing between today and the explosion of Infrastructure Solar are a few innovations. Traditional flat crystalline solar modules can be added to existing infrastructure such as rooftops using mounting rails and attach points that depend on the type of roof material and structure. These flat solar modules work well on rooftops with large, flat, generally south-facing surfaces. When mated with MLPEs like a microinverter, each flat solar module’s generation is optimized. Localized shading only affects the generation of the shaded module, unlike string inverters where the performance of shaded solar modules can affect the performance of other solar modules sharing the same string inverter. Or when rooftops have multiple flat surfaces with different slopes and orientations, flat crystalline solar modules with microinverters per module perform optimally as well. However, these flat crystalline solar modules are big. A typical 60-cell solar module is in the 65 by 40 inch range, and getting bigger. Sunpower is now producing a 128-cell, 435 watt solar module that is a whopping 82 by 41 inches and over 20 percent efficient!

While bigger and more efficient is better for solar farms and most rooftops because the dollars per watt decrease, bigger is worse when the goal is to cover existing infrastructure. Curvature is the problem. Flat crystalline solar modules are, well, flat and rigid. They do not bend, so the bigger the flat crystalline solar module the less curvature it can effectively cover. Much less existing infrastructure can be transformed into solar energy generating devices with big, efficient crystalline solar modules.

Flexible Solar Modules

Flexible amorphous-silicon and CIGS solar modules can more easily attach to and cover existing curved infrastructures like poles and arms, but the cell efficiencies are less than crystalline cells and the orientation of bypass diodes between cells may or may not align optimally for the infrastructure being wrapped or the position of the sun throughout the day. When not ideally oriented, module generation performance suffers. For example, wrapping an amorphous silicon solar module designed to lay flat between spars on a metal roof, around a vertically oriented cylinder like an aluminum light pole, yields less than optimized generation because the cells were not wired with this geometry in mind.

The first innovation needed to unlock Infrastructure Solar combines the best of both crystalline and flexible solar cells into an articulating solar module; a solar module designed to transform existing infrastructure into optimized solar energy generating devices by attaching to and covering with articulating facets comprised of crystalline solar cells. This new class of solar module is comprised of two or more facets that articulate relative to one another, while each facet is comprised of one or more solar cells whose size and shape is determined by the geometry of the existing infrastructure being transformed and whose orientation relative to the sun is the same.  The size and shape of a facet’s crystalline solar cells need not be square or rectangular, but instead should be determined by the infrastructure being transformed and its curvature. These cells may take on the shape of all kinds of polygons such as triangles, pentagons, hexagons, octagons and the like, all to facilitate covering arbitrarily curved, already standing infrastructures.


Second, like the optimization benefits gained from mating microinverters with today’s solar modules, MLPEs must be applied more granularly than a single 60 or 70 or 128-cell solar module. Each articulating crystalline cell, or each group of crystalline cells that articulate together (i.e., facet), must be mated with an MLPE to optimize its performance regardless of orientation relative to the sun. Generalizing this notion and extending it across years of technological advancements, the logical result is the incorporation of a direct-current, solid state, Maximum Power Point Tracking (MPPT) power optimizer directly into each facet, and then sharing a single, separate, grid-tied inverter across numerous so-equipped facets to create an articulating solar module. An Infrastructure Solar system is then constructed from as many articulating solar modules as are necessary to cover the existing infrastructure being transformed.

Power Optimization

Obviously economics plays a big part in Infrastructure Solar too. The previous two technical innovations open up the market, but the dollars per watt must also be compelling. Balance of system costs should be less for most types of Infrastructure Solar because the infrastructure already exists and the cost is already sunk. However, a new type of articulating solar module employing more granular MLPEs will drive up system cost, initially.  Fortunately, if we have learned anything from the solar boom these past several years it’s the fact that solid state technologies and manufacturing processes consistently outperform predictions about economies of scale, solar modules and MLPEs included.

Data Center

The final innovation that will unlock the potential of Infrastructure Solar involves big data. Microsoft and Google both have truly massive geocoded data sets along with ecosystems seeded with platform development tools and services to extend these data sets. Think about the mapping app on your mobile device and all the supporting data overlays you see when following directions, like restaurants with their menus and star ratings, gas stations with their gas prices, etc. Now what if this same machinery were used to geocode existing infrastructure like street lights, traffic signals, water towers, and so on, and then overlay these locational data with ever more detail like height and diameter of street and traffic poles, easement ownership information for the land on which these poles reside, specifics about the below-ground power available to the poles like voltage and the nearest circuit panel, and so on? This level of detail would dramatically reduce the cost of standing up the first wave of Infrastructure Solar. Infrastructure will need to be cherry picked initially because economies of scale will not have kicked in, so easily and cost effectively identifying these cherries will be crucial initially. Yet even after this first wave helps to drive down system costs, the data will remain invaluable as a tool to reduce balance of system costs, perpetuating the economies of scale cycle.

Eleven years ago it was The Long Tail of the Internet. Eleven years from now it may very well be The Long Tail of Solar, with every size and shape of existing infrastructure transformed into solar energy generating devices. When summed, all these small, niche, solar generating systems will dwarf the kilowatt-hour capacity of the big solar farms just like Internet search advertising did for niche products relative to big product hits. Maybe then we will finally be able to put the 1 kilowatt of direct sunlight that hits every square meter of the Earth’s surface to good use.

Roadside Resiliency

It’s an occupational hazard I suppose, this compulsion I have to examine roadside infrastructure everywhere I go. Street lights, traffic signals and control cabinets, bus and rail stops… they all smell of underutilization, and there are a lot of them. Why not repurpose? Why not leverage that real estate like American Tower Corporation did when they ingeniously bought up strategically located real estate in the 90s, stood up towers and waited for cellular and broadband companies to pay them for placement? Instead of delivering connectivity, however, this roadside infrastructure could be delivering energy. What’s more, because this infrastructure resides along the low-voltage, secondary distribution end of the electricity grid – the edge as it were – energy delivered here offers unique benefits.

Resiliency is one such benefit. Grid resiliency is a fundamental tenet of the smart grid, and one whose import swells along the eastern seaboard, which is still reeling from Superstorm Sandy. In October of 2012 Sandy delivered a wallop that caused nearly $62 billion in carnage and 13 days without power, punctuating the fragility of our nation’s electrical system. The situation would have been different had roadside infrastructure been upgraded with solar generation and battery storage. Imagine an outdoor lighting microgrid, or a traffic intersection microgrid?

Wait a minute, what’s a microgrid? A microgrid is a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid and that can operate in either grid-connected or “island” mode. Translating, that means an outdoor lighting microgrid is a lighting circuit with an Automatic Transfer Switch (ATS) at the head end interconnection point to the grid, with solar generation, battery storage and lighting loads all residing behind the switch on the same circuit. When properly sized for a particular location’s solar generation capability and then islanded, the solar plus battery microgrid can power the lighting system load indefinitely even though the broader electrical grid is down.

Outdoor Lighting Microgrid

In a similar fashion, a traffic intersection microgrid is a low-voltage circuit on the secondary distribution system that is fronted by an ATS and includes solar generation, battery storage and loads in the form of traffic signals, red light cameras, pedestrian crossing signals, overhead lights, etc. With the right amount of battery storage for the loads and available sunshine, this intersection can also remain functional until grid power returns. Together, outdoor lighting and traffic intersection microgrids would have allowed vehicles and pedestrians to safely get around for all 13 days of Superstorm Sandy’s grid calamity, had they been in place.

Traffic Signal Microgrid

How hard is it to repurpose an already standing outdoor lighting system or traffic intersection into a microgrid? Today, it’s not as hard as you might think, though it does require some unique experience, a healthy dose of ingenuity and an ecosystem of key partners. One of the technical innovations that have emerged recently to simplify such infrastructure reuse is the grid-tied AC battery storage device. Companies like STEM and CODA Energy play in this space, solving the problem of high demand charges in places like California. Being grid-tied AC devices, these battery systems can be added to an existing AC circuit where they will source or sink energy on the circuit using cloud-based predictive analytics. When reducing peak demand charges the algorithm lowers monthly energy bills by predicting energy usage patterns and then deploying stored energy at precise times to reduce peak loads.

When put to use in a roadside microgrid the predictive analytics would be different, but the concept is the same. Predicting energy usage patterns is easy for outdoor lighting since there is very little variance in the load characteristics across a set of luminaires. A traffic intersection may be a bit more challenging to the extent energy usage depends on traffic, but this level of prediction pales in comparison to a commercial energy customer’s load characteristics, so it is well within scope. A roadside microgrid, however, presents a different challenge on the energy releasing side. The goal is no longer reducing peak demand but instead, ensuring there is as much energy as possible to power the microgrid’s loads should the broader electrical grid go down.

By itself that goal is easy; continuously top off the battery storage and then anything else can be released through the interconnection point to the broader electrical grid. Unfortunately the situation is not that simple. These distributed generation and storage assets can be used to help manage the efficiency and utilization of the distribution system, which may be at cross purposes with keeping the microgrid loads on as long as possible. Happily, predictive analytics can help. Storms like Superstorm Sandy do not materialize instantaneously. They evolve. Incorporating meteorological data is already part of the predictive analytics. When mated with rooftop solar, these AC battery storage devices predict how much sunshine and therefore how much energy a system will generate in the hours and days to come. This same technique can be used with roadside microgrids to prioritize storage over distribution system management in the hours and days preceding a widespread weather event.

Because of my compulsion, when I hear and read about the “smart grid” I imagine roadside resiliency – underutilized roadside infrastructure transformed into microgrids that help distribution system operators manage their systems in their spare time but then step up to deliver safe locomotion during emergencies. Now isn’t that smart?

Duh, It’s DER!

What’s in a name? Sometimes, it’s everything. DER, or Distributed Energy Resources, is the name given to a collection of energy solutions defined by small scale renewable energy sources combined with advanced information and control technologies that can be aggregated to provide reliable energy necessary to meet regular demand. Examples include: renewable generation, energy storage, energy efficiency, demand response, electric vehicles and any combination thereof.

Today DER means rooftop solar, with a little bit of Electrical Vehicle (EV) charging sprinkled here and there. Both rooftop solar and EV charging occur behind-the-meter, on private residential or commercial property, beyond the influence of the Investor-Owned Utility (IOU). In fact much of the rooftop solar going in today is provided by third party leases from companies like Solar City and SunPower, who are in direct competition with IOUs. Competition for rooftop solar DER is fierce, making it challenging for IOUs to play a significant role, especially when hamstrung by existing business models involving fixed rates of return. The only viable way for IOUs to leverage this class of third party (and customer-owned for that matter) rooftop DER is through program incentives. With the right incentives, participating customers can be persuaded to source energy from rooftop arrays or sync energy into EV batteries at meaningful times to the IOU just like they do with energy efficiency programs targeting thermostats, but the impact is small and indirect and may conflict with the financial benefits of these third party systems.

What will DER mean tomorrow? California may be first to decide. California has mandated (AB-327/Rulemaking14-08-013) that their IOUs deliver Distribution Resource Plans (DRP) by July 1, 2015 that include high levels of DER. In addition SB-43 , also known as “Community Solar”, mandates solar for everyone, not just those folks with sufficient rooftop real estate and credit scores. Both of these aggressive California mandates share a common problem – siting.

If you believe the Distribution System Operator (DSO) model is where we are headed, then the answer to the siting problem for DER and Community Solar may be along the low-voltage secondary distribution system, before-the-meter, on existing infrastructure and easements so that DSOs can own and operate these resources. Imagine solar generation added to existing outdoor light poles and then at the head-end of the lighting circuit, energy storage and power regulation are sited, sharing a common easement, interconnection point and information/control solution. Voilà, Local-Area DER!

Local-Area DER

Such a Local-Area DER solution has many benefits including:

  • Small-scale capacity with power regulation
    • Solar generation plus battery storage
    • Dispatch-able and load shifting
    • Resolve existing power quality issues w/regulators
    • New high-quality capacity w/smart microinverters
  • Located “before-the-meter”
    • DSO owned, operated & controlled
    • Meets incremental demand with co-located supply, reducing transmission losses
    • Adds value to distribution “wires”
    • Low-voltage: 120/240/480V, single or three-phase
  • Utilizes existing infrastructure
    • Quick, easy and economical to implement
    • Reduce or eliminate land use and permitting issues
    • Build up balance and reliability across interconnections from the edge
  • Deployable in lock-step with behind-the-meter grid issues
    • Similar sizing to “behind-the-meter” DER
    • Co-located along the same “wires” with issues
    • Economically scaled as grid issues scale

In addition to these benefits, siting Local-Area DER along existing roadside infrastructure where low-voltage distribution “wires” reside is democratic. Everyone lives near roadways, whether renting an apartment or residing in a structure incapable of hosting a rooftop solar installation, so Local-Area DER delivers on the Community Solar promise of environmental justice too.

Local vs Wide-Area DER

Wide-Area DER, sited further up the distribution system hierarchy at the sub-transmission or primary distribution level, does not deliver the same degree of benefit. Real estate remains a challenge to procure. Even though the amount of land required is less than a full-scale gigawatt solar farm, acquisition, permitting, land use, environmental and legal issues still abound. Plus the energy must traverse the distribution system to get where it is needed most, which may necessitate some of the very same switch and wire upgrades DER is intended to avoid.

There are scale matching issues as you move up the hierarchy as well. The number of circuits that can be addressed with a single solution increases as you move up the hierarchy, but the ability to target some circuits out at the edge but not others requires additional investments in power routing solutions. System sizing up the distribution system hierarchy can also be challenging. How much generation, storage and power regulation is needed today across all the rapidly evolving circuits, and tomorrow, and the day after that? IOUs are very skilled at modeling circuits and predicting load, so this would not seem like a concern on the surface. However, these well-oiled processes cannot match the pace of unpredictable change unfolding behind the meter.

Instead, a single circuit with occasional bi-direction power flow, power factor and harmonic issues can be targeted with a single circuit-sized Local-Area DER solution leveraging land and infrastructure whose cost is already sunk. Comparable sizing combined with co-location before the meter along the same circuit resolves these issues quickly and economically and helps the DSOs maintain control over their system while meeting their ever present reliability expectations.

So, what’s in a name? If the name is DER and it is preceded by the adjective Local-Area, it could be everything.


I love architecture. I also love technology, so blending the two is a fantasy, or so I thought. Turns out my day job in highly distributed renewable energy forces me to rethink all of the systems in a home in the context of the latest efficiency, generation and storage technologies. Doing so is hard and turns my fantasy into some kind of Franken’home, stitched together from bits and pieces across several industries. Here’s what I mean.

First and foremost, my dream home is perched on a low-bank waterfront parcel on the Puget Sound near Seattle, Washington. If you have never meandered a salty sound beach, dodging star fish and geoducks and inhaling that pungent kelp-filled fragrance, you are missing out. But I digress…

Of course my dream home is efficient, adhering to the latest passive solar home design principles including a highly performant building envelope with carefully managed airflow, orientation that maximizes seasonal use of sunlight and a suitably sized thermal mass integrated into the home design as concrete flooring and walls. Combined these passive solar principles ensure my dream home barely sips energy.

Even so, today’s modern life filled with electronics comes at a price; the auxiliary energy load is high. Multiple computers, media equipment, appliances, electric car chargers and the like all require energy. Plus Seattle is not exactly bathed in sunshine all year long like the Southwest. To meet this load above and beyond the passive solar design, my dream home has rooftop solar, perhaps an 18 kilowatt installation. Leveraging the beachfront location, a 2 kilowatt micro-wind turbine takes advantage of the prevalent winds and helps to offset the load as well. Solar and wind variability necessitates storage, so my dream home also has a 30 kilowatt-hour, lithium-iron-phosphate battery storage system to smooth out this variability and accommodate the long winter nights at 48 degrees North latitude. Even with all this onsite generation and storage capacity, however, I still believe there will be long-term value in remaining connected to the electricity grid so my dream home includes a net meter with a connection to and relationship with my local electric utility.

USB Ports

Now that energy is covered, what’s next? Lighting. All lighting, indoor as well as outdoor and landscape lighting, leverages dimmable LED technology. Moreover, dedicated DC-only lighting circuits are built into my dream home and powered by the DC battery system. Doing so eliminates the incredible redundancy of converting natively DC lighting to AC every time it connects to power. The battery system is charged by solar and wind, which of course are both variable DC, and then on rare occasion by the AC connection to the electricity grid when renewable fuel falls short of demand or becomes more economical. In turn, the battery system serves to smooth out this variability, delivering consistent DC voltage for all lighting. This consistent DC voltage also gets used throughout my dream home to power DC accessories via Universal Serial Bus (USB) interfaces integrated everywhere. Imagine how convenient your kitchen island and counters, and even bathroom counters, become with traditional AC power receptacles plus USB ports for charging the myriad electronic devices now standardized on USB cables for power.


While the greater Seattle area ranks low for solar irradiance, rainfall is abundant, so rain water is carefully managed. All water on the structure and surrounding flat-scapes is collected, filtered and stored in an underground cistern, along with gray water generated inside the home from lavatories, tubs, showers, etc. Gray water in the cistern is then recycled for use in flushing toilets and for landscape watering.

Radiant Heat

On to heating. Have you ever experienced in-floor radiant heat, also known as hydronic radiant floors? The experience warms the soul (or sole anyway.) Because your feet are warm, and heat rises, the experience is very satisfying. It can also be very efficient, especially when embedded in concrete floors serving as thermal mass and mated to the latest solar water heating technology. Sure, a pump is required to recirculate the high energy-density fluid through the hydronic tubing, but very little electricity is required to actually heat the fluid. Only when the concrete flooring cools below the comfort level does in-floor radiant heat even need to kick in, and then only when there’s insufficient sunshine does the fluid need to be heated with an auxiliary electric heat exchanger. So my dream home includes in-floor radiant heating with a solar heat exchanger and electric backup.


What about cooling? The greater Seattle area is not known for its long stretches of 100+ degree days in the summer, but given the location of my dream home on the Puget Sound, taking in the view is paramount. View means glass, and glass means cooling load, especially when facing south or west. In-floor or in-ceiling radiant cooling is an elegant solution for all the same reasons in-floor radiant heating is. Unfortunately, radiant cooling is subject to condensation issues when relative humidity is high, which is the case in Seattle, so this solution will not work. Instead, careful attention is paid to passive solar design details like glass properties and thermal conduction between the poured concrete floor and the cool earth below, which dramatically reduces the cooling load overall. Then an efficient air-to-air heat exchanger like the one from Daikin is used for spot cooling where and when necessary.


My Franken’home is lying on the operating table all stitched together, an amalgamation of disparate yet highly efficient systems. It is not, however, alive. To make my dream home live, it’s not lightening I need but a control system, and this is the biggest gap in today’s available technologies. Nest, recently purchased by Google for a whopping $3.2 billion, helps show the way with its clever activity-based learning and optimization. My dream home takes this idea and extends it throughout all systems in order to give it life. Sensors abound. Each room or area in my dream home has its own hydronic radiant floor zone, lighting zone, window covering or shading zone, temperature sensors at ground level, torso level and ceiling level, occupancy sensors and lumen sensors for brightness. These sensors provide the real time feedback loop necessary to optimize the various systems over time. Plus each room or area has a manual control for temperature, lighting and shading. Then like Nest on steroids, over the course of a year’s worth of seasons, my dream home’s control system learns the relationships between season, time of day and activity – reinforced by manual adjustments to systems – and derives common default behaviors with the twin goals of hands-free comfort and energy efficiency most of the time. Overrides will occur all the time, and will remain easy, but with more and more time the activity trends will emerge that enable the system to be comfortable and energy efficient, automatically.

Energy efficiency in the context of occupant comfort has more to do with load management. The other dimension of efficiency in my dream home with onsite energy generation and storage plus a connection to the electricity grid involves economics. When should onsite energy generation be used directly by house loads, stored in the battery system or inverted through the utility’s meter onto the grid? The answer lies in the relative costs and benefits of the various options based on the time of use. Utility energy prices over time are one key input. For example, if energy is being generated when the utility will pay a premium, then this energy is inverted onto the grid while the house runs off the battery system. However, if historically the next day has a particularly high demand for lighting and USB device usage and there is insufficient time to fully top off the battery system overnight, then some of the renewable energy generation is used to charge the battery system instead.

Meter and CT

Like the temperature, lumen and occupancy sensors used to optimize the energy loads of comfort systems, optimizing energy economics needs sensors too. These sensors are called meters, with current transformers (CT), and they measure energy, power, current, voltage and a host of more esoteric power parameters. My dream home includes granular energy monitoring. Each of the comfort systems – heating, cooling, lighting and shading – has its own meter and CT for individual monitoring. The heating system utilizes a pump and backup electric heat exchanger so each of these sub-systems is individually monitored with its own meter and CT. All major appliances are individually monitored too – refrigerator, oven, induction cooktop, microwave, dishwasher, clothes washer and dryer, media equipment and EV car charger. All DC USB accessory circuits are monitored together with a single meter and CT, as are the conventional AC power receptacle circuits, so individual accessories won’t be identifiable but accessory energy usage as a whole will be. Energy generation systems are also individually monitored. Together, all this monitoring information gets used to learn and optimize the economic performance of my dream home over time.

This level of whole-house system integration centered on simplicity for the home owner does not exist today, which seems shocking. It is such an obvious problem and all the bits and pieces exist separately, yet the path to integration redemption is littered with carcasses of startups and mature multinationals that have tried and failed. The market for whole-house system integration and automation is fragmented, as are standards. Plus the sales channels are wide and varied, a testament to the many ways such systems come to be in a house. This is a tough business challenge, but one that I hope will come along for the ride as energy efficiency, generation and storage innovations needing integration and automation flourish in the coming years.

One additional gap in today’s technology keeps my stitched-together Franken’home from getting off the operating table and really living: fire. I love fire. The ambiance and warmth it provides as an aesthetic design feature inside and outside is difficult to beat. More importantly, I love to grill. My dream home has an outdoor kitchen worthy of a Food Network television show, though it is covered. We are talking the Seattle area after all. Yet fire needs fuel, and fire fuel is neither renewable nor green. It’s a conundrum. On second thought, it’s not so much a technology gap as a personal problem. I am too unevolved to live without fire, but may be exactly unevolved enough to work for Geico Insurance.

The Breakup Letter

T-Mobile is running a clever little ad campaign urging mobile phone customers to send their controlling carriers a breakup letter. It’s all about early termination fees, which keep customers tethered to their current carrier for the duration of their contract. These fees help carriers recoup the cost of subsidizing the mobile phone hardware – for example, a $499 smartphone can be had for free with a 2-year contract. If the customer wishes to leave before the carrier can earn out their $499 plus a tidy margin, the carrier recovers the unpaid balance via early termination fees.

I wonder whether energy customers would like to send their controlling utility companies a breakup letter too. Residential customers in Hawaii and commercial customers paying demand charges in California probably like the idea quite well. Their electric utilities, asleep at the wheel while innovations in energy efficiency, generation and storage reduce demand for their product, have been levying early termination fees of a different sort. Imagine hundreds of millions of dollars tied up in a centralized, coal-fired power plant. Ten years ago the plan was to earn out this whopping upfront investment – plus a reasonable return – over the next 30 years from $$/kWh paid by a captive audience of energy customers. Trouble is, the audience is no longer captive. Energy customers are being more efficient. They are buying or leasing rooftop solar and in some places, going completely off grid. As demand for the utility’s product wanes, meeting this 30-year obligation requires these electric utilities to increase their energy prices in order to keep the shortfall at bay. Increasing energy prices, in turn, further decreases demand and perpetuates the cycle. Energy customers unwilling or unable to employ efficiency, generation or storage innovations are left behind to pay these higher energy prices – akin to early termination fees.

Dramatically, the Rocky Mountain Institute just published data crisply answering the question of when it will become economically viable to defect from the energy grid entirely using solar photovoltaic (PV) panels plus lithium ion battery technology. The answer is an unequivocal “now” in places like Hawaii and within the next 10 years more broadly. More and more utility customers will be terminating early, well ahead of when the electric utility will recoup its earlier investments in centralized energy generation.


As a result, customers are breaking up with their wireless carriers and their electric utilities with more breakups on the way. How do you connect to the Internet at home – digital subscriber line (DSL), cable modem, fiber, wireless, satellite, broadband over powerline (BPL)? According to the Organization for Economic Cooperation and Development (OECD) nearly 70% of all U.S. households have broadband connectivity and the mix of technologies used lays out like this:


Penetration of broadband internet access has fundamentally shifted the way media content gets consumed. Most of Gen Y – raised on the Internet – consumes their media content via the web. Armed with their Netflix, Hulu Plus and other Internet-based content subscriptions and the control they provide over what, when and where, Gen Y is shunning traditional television content from the Comcasts and DirectTVs of the world. The only gap in this strategy is live sports content. Often this gap gets closed at bars where the social dynamic of enjoying live sports with friends and food service trumps the convenience of home. Plus, more and more live sporting events can be watched in real time on the Internet via applications like ESPN’s WatchESPN family of device-specific, content-streaming applications for homebodies.


Broadband equals streaming, and broader band is better. Innovations yielding faster and faster connection speeds are driving the penetration of fiber throughout major metropolitan areas. Fiber is even winning in rural Greenfield developments that put the “ease” in easement, helping to keep the cost per foot of delivering fiber lower than fiber in urban areas rife with right-of-way issues. Before long, fiber companies will own the connection to the home, like electrical utilities, and yet this connection will be under siege soon as well.


Ever wonder why there are two different wireless networks; why your smartphone shows bars of connectivity to your cellular network while also providing Wi-Fi access to your local home, hotspot or work network? By any chance do you have Voice Over Internet Protocol (VOIP) phones at the office, or even at home via providers like Vonage? A massive shift is afoot, fueled by innovation. Convergence is coming. With the rollout of fourth-generation / long term evolution (4G/LTE) technologies in the cellular networking world comes the acceptance of data, not voice, as the dominant packet being marshalled around. Data means packet switching using the Internet Protocol (IP). Voice is not left out entirely; it too can obviously be marshalled around using IP, so all networks are converging on a single, flat, IP-based technology. Speeds are increasing as well. A third-generation carrier network (3G) can deliver speeds of 1.5 to 3 megabits per second (Mbps) while a 4G/LTE network can deliver 10 to 20 Mbps, today. These speeds are already as good as or better than DSL. Plus the theoretical limits for 4G/LTE approach 100 Mbps down and 50 Mbps up, landing in the realm of fiber solutions. Work is already beginning on the fifth-generation cellular network (5G), with the goal of achieving a flat, all IP-based network and theoretical speeds in the 1 gigabit per second (Gbps) range.


Another breakup letter is in the works. This letter severs ties with Internet Service Providers (ISP) providing underground connectivity (i.e., DSL, cable, fiber) and, ironically, puts mobile carriers front and center once more, but not necessarily the same mobile carriers we know and love today. Coming full circle back to mobile telecommunications purveyors is not the most interesting realization, however. Imagine a world where you do not need to be tied to an electric utility for power or an ISP for connectivity. No ties mean freedom. Sure, you could plop your super energy efficient house with Gbps connectivity anywhere there is sufficient sunshine, wind or both, and a wireless broadband access point. But that is the least interesting ramification, enmeshed as it is in the larger socioeconomic ebbs and flows of urban versus rural renewal. Even more mind-bending are the truly mobile notions. All-electric vehicles covered in flexible solar collecting skins and sporting Gbps connectivity would rarely need to dock, would provide passengers and surrounding vicinity full fidelity access to the Internet, could participate in a bevy of two-way, data-intensive telemetry services and be commonplace. Mobile telemedicine clinics would deliver Western-style medical services to remote, impoverished areas of the world, economically. Beach umbrellas made from foldable solar-collecting fabric, a handle filled with batteries, a Wi-Fi hotspot and a 120V AC receptacle would dot sandy shores everywhere.

As the inspirational music fades, keep the breakup letter in mind. If you are not penning a letter to Verizon Wireless or Duke Energy or Comcast you may find yourself paying too much and labeled a Luddite. After all, innovation changes everything.