Wednesday, December 5, 2012

Resilience and Renewables

Resilience and Renewables
By Joy Hughes

How can our renewables policy at all scales respond to the lessons of the floods, droughts, winds, and ice storms of 2011-2012? The value of on-site solar systems with storage that can provide backup power is now crystal clear. Microgrids including community scale solar and battery storage might be able to take entire neighborhoods off-grid when necessary. Happily, the same steps that can make communities more resilient will also provide a path to a society powered by 100% renewables. It’s important to take the lessons of hurricane Sandy into account when designing community solar policy.

Climate Adaptation and Solar Policy

Catastrophic climate change is upon us. Recent measurements show that the climate is more sensitive to increased carbon dioxide than was previously thought. Paleoclimate data show that even under natural conditions, the Earth’s climate doesn’t always change smoothly – sometimes, huge changes in ocean and atmospheric patterns can occur in the space of a decade or less. Under such conditions, human infrastructure is pushed past its tolerances. The electric grid in particular is vulnerable to extreme weather events, solar storms, and intentional attack. Personnel and resources are stretched thin as the infrastructure endures climate extremes, and as it ages.

Sustainability involves re-envisioning our relationship to our environment, urban and rural. Solar panels serve multiple purposes – climate change mitigation through reduced carbon emissions, climate change adaptation by providing backup power in the case of storms, and immediate disaster relief by providing solar-powered generators in impacted areas. Solar installations have an intimate relationship with the people, animals, and plants that live among and around them.

Solar policy has most often been based around a mitigation-only approach that involves getting as many green electrons onto the grid as possible in the most cost-effective way. This can lead to outcomes like grid-tied panels that can’t power your house when the grid goes down – right when you need them most! These decisions were made in the 2000s, before the “age of consequences” really got under way. Sandy has awakened us to the need for a new approach.

Changing assumptions around renewables

Let’s look at how assumptions around renewables have changed since the mid 2000s, which can help us decide where course corrections in policy are needed.

1.     Climate change impacts have accelerated faster than most predictions.
2.     Solar PV costs have declined rapidly, and European countries have demonstrated the potential of distributed solar.
3.     According to Secretary of Energy Steve Chu, new battery technologies promise a similar decline in energy storage costs.
4.     A community solar movement has emerged, with an emphasis on local control, stakeholder inclusion, and socioeconomic parity.
5.     Crowdfunding and microfinance have moved into the mainstream.
6.     A number of utilities have developed prototype projects with some combination of high solar penetration, battery storage, and islandable microgrids.

Solar policy based on the Resilience Paradigm

The following changes in solar policy can help us make communities more resilient and at the same time provide a path to a society powered by 100% renewables.

Solar gardens

  • Opportunity: Community shared solar installations (“solar gardens”) allow multiple subscriptions to a single offsite solar array, making solar power available to the majority of homes and businesses that have shaded roofs, to businesses and people who rent, and to those who occupy multi-unit buildings. Through the use of virtual net metering, subscribers receive credit for the power produced by their panels on their electric bills.

  • Policy changes: Solar gardens legislation and policy can help provide resilience everywhere; it would be particularly fitting for states affected by hurricane Sandy to enjoy the benefits of such resilience. Feed-in tariffs, or CLEAN programs (Clean Local Energy Accessible Now), can be combined with virtual net metering to provide pricing for community solar programs.

Aggregating installations into solar gardens

  • Opportunity: With microgrids in place in Lower Manhattan, generators in a private office building could provide power for hospitals and relief centers. Solar gardens can be located over parking lots and as “solar tunnels” over roads, and provide multiple benefits including runoff management. Solar panels can work with green roofs, providing additional cooling shade and wind protection. Solar can be worked into the urban environment as awnings, dining umbrellas, streetlamp reflectors, bus shelters, and more. Each grid-connected distributed panel can be part of a single community-owned “virtual solar garden” which aggregates the output of multiple installations within a microgrid. Roofs that have extra space for solar beyond the building’s own needs can add extra panels and include them in the virtual garden at a fairly low marginal cost.

  • Policy changes: At the state and utility level, the ability to aggregate multiple installations into a solar garden should be encouraged, especially for complexes of multi-unit buildings.

Emergency backup power

  • Opportunity: Community solar crowdfunding projects often provide solar for community centers, houses of worship, and schools – just the sort of places that can serve as shelters, relief distribution centers, information hubs, and charging stations. Battery standby power can make this possible, thereby increasing the value of these projects.

  • Policy changes: Philanthropic organizations and government entities can provide grants to enhance community scale on-site renewable energy projects to include emergency backup power.

Energy storage systems

  • Opportunity: Energy storage can increase the amount of solar power the grid can take by reducing spikes in power, and by making the output of solar arrays more predictable. During heat waves, when air conditioners are on after dark, battery storage can extend solar’s ability to support peak power into the evening. Utilities pay premium rates for power in these situations, and can see economic value in having storage on-line. Community-level finance can create “battery gardens” that sell power to the utility when supplies are tight.

  • Policy changes: The federal government can extend the 30% investment tax credit to energy storage systems (the STORAGE Act), and utilities can provide incentives for grid-connected battery storage. Solar gardens laws can be extended to include energy storage.


  • Opportunity: Existing feeder circuits (which usually serve a few hundred to a few thousand people) may be converted into microgrids, containing solar panels, storage, backup generators, and combined heat and power (CHP), as well as supporting demand response programs. Microgrids can go off-grid and provide emergency power when the larger grid goes down, or isolate a fault within the microgrid from the larger grid, if necessary. A great example of this “self-healing” grid is Portland General Electric’s Smart Feeder project, which includes solar power, battery storage, and generators. Switches are installed to isolate the feeder line from the main grid, when needed. A citizen’s group in North Westchester County in New York State has proposed a feeder-to-microgrid project.

  • Policy changes: The conversion of feeder lines to microgrids should be encouraged by providing incentives to utilities at the state or municipal levels.

Solar that supports the local grid

  • Opportunity: The Interstate Renewable Energy Council’s Community Renewables Model Program Rules provide a framework for state legislatures, public utilities and municipal utilities to establish community solar programs. According to the rules, “…the value of the kWh credits for the host Subscriber and those Subscribers on the same distribution feeder” are at retail electric rates, while other subscribers pay a charge to the utility for delivering electricity.

  • Policy changes: Incentives for subscribers on the same feeder as the solar garden can encourage the development of solar that can support the local grid.

Financing models for all

  • Opportunity: The Occupy Sandy outgrowth of the Occupy Wall Street movement has demonstrated how wealth inequity has an impact on disaster preparation, relief, and recovery. Solar power should be made available to all, not just in times of emergency. With the right financing models, solar subscriptions can be made available to the “middle middle” class as well as the working poor, disabled, and retired people. Everyone uses electricity – making solar available to all is good business.

  • Policy changes: Municipalities and counties can act as guarantors – subscribers of last resort – making possible bankable community solar for all. Municipal bond issues can support community solar projects.

The Future of Community Solar

As community solar policy is developed in more and more states, let’s keep resilience in mind while designing a solar policy that supports small scale, local, community owed facilities, and includes all cultural and socioeconomic groups. Let’s plan carefully to build a new grid that is resilient to the future impacts of climate change.

Special thanks to Becky English and Rosana Francescato for their work on this paper.

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