Solar+Storage in Schools: The No-Brainer Solution for Clean, Resilient Shelters

Author: Todd Olinsky-Paul, Clean Energy Group | Project: Resilient Power Project

blogphoto-desoto-elementary-school-FloridaEver notice an obvious solution to a problem that nobody else seems to have picked up on?

That’s what happened in Florida in 2012 when the Florida Solar Energy Center, working closely with the state energy office, began a program to equip public schools designated as community hurricane shelters with resilient solar+storage systems.

Given the pace of technology and market development, both solar PV and batteries were more expensive at the time. In addition, since the program was funded through the federal ARRA program, US-manufactured equipment was required, rather than cheaper imported components. Still, Florida’s E-Shelter program has managed to put solar+storage systems at more than 115 schools so far, at an installed cost of $74,000 to $90,000 per school. Costs were low because the state took a “cookie cutter” approach and kept the systems small – a typical system consisted of a 10 kW solar PV array, with a 48 kW battery, just enough to keep lights and electrical outlets operating during a grid-disrupting natural disaster. The state was also able to negotiate a volume discount by using a single installer for the entire state. School received the systems at no cost, and program staff calculated that each school would save around $1,500-$1,600 per year on electricity costs, in addition to serving an important community function during hurricanes and other disasters.

Why is this a no-brainer? Well, for one thing, every community has a school.  Schools tend to be centrally located, they can accommodate large numbers of people, they have necessary facilities like kitchens and bathrooms, they are handicapped-accessible… in other words, they make great emergency shelters, which is why public schools serve as designated shelters in many communities.

A second reason schools are great candidates for solar+storage technology is that they often have lots of space for solar panels, including both on the roof and on the school grounds. In fact the Solar Foundation recently released its National Solar Schools Census, which identified 3,752 schools across the nation that are already equipped with solar energy systems. That means there are schools in many states that are ripe for a solar+storage retrofit.

Of course, working with schools presents challenges as well as opportunities. Decisions ultimately rest with local school administrators and school boards, meaning that E-Shelter Program staff had to sell the idea to each school board. Because school administrations tend to turn over rapidly, systems generally had to be completely installed within a year.

Florida’s program will be examined in detail in Clean Energy Group’s upcoming webinar on resilient power in schools, scheduled for Tuesday, March 31, at 2 p.m. Guest speakers include Susan Schleith of the University of Central Florida’s Solar Energy Center, and John Leeds, Senior Management Analyst at the Florida Office of Energy, who will discuss the Florida program’s success, lessons learned, and future initiatives. We will also hear from Avital Szulc of the third-party solar+storage provider A.F. Mensah. Mensah is working on solar+storage systems at schools in New Jersey. Szulc will discuss the company’s model for solar+storage financing, and how these systems can capture value streams by participating in energy markets (thus providing a market-driven model for resilient power deployment, rather than relying on government grants). Additional speakers Adje Mensah, Peter Mendonez, and Drew Adams will be on hand to answer questions.

Resilient Cell Towers: An Idea Whose Time Has Come

Author: Todd Olinsky-Paul, Clean Energy Group | Project: Resilient Power Project

blogphoto-cell-towerWhen considering critical infrastructure for resilient power solutions, states and cities often tend to focus on the usual suspects: public shelters, medical facilities, transportation hubs, fueling stations, first responders, emergency management facilities. Thinking a bit more outside the box, we might add water and wastewater treatment facilities and multi-family housing to the list.

One type of facility that is often overlooked, perhaps because they are largely unseen, is cell towers. Typically sited in remote locations, these towers don’t require much electricity to function… but they do require some, and if their supply is cut off during a grid outage, having a place to charge your cell phone won’t do you much good.

Supporting cell towers with distributed generation is not a new idea. Thousands of cell towers around the world run on diesel generators, usually because they are sited where there is no easy access to the electric grid. Fuel cells have also been used to provide backup power to grid-tied cell towers, with good results. For example, more than 60 cell towers in the Hurricane Sandy disaster area, which had been fitted with fuel cells for backup power, continued to operate throughout the disaster, while others failed.

Of course, the drawback with both diesel generators and fuel cells is that they require fuel to run.  In the case of 22 NYSERDA-supported fuel cell generators at towers, fuel tanks had to be replaced every three days to keep the towers operating during the grid outage. Fuel tanks are also vulnerable to theft, especially during emergencies when fuel may be in high demand and short supply. And in the case of grid-connected towers, backup generators sit idle 99% of the time while the grid is up and running, representing sunk costs.

Solar PV and batteries offer an alternative solution that not only eliminates the need for fuel deliveries and onsite storage tanks, but can function year-round to reduce electricity costs. This is important, as electricity costs contribute up to 15% of total cellular network operating costs for grid-tied towers; this percentage can increase up to 50% for towers in remote locations, due to the cost of running and maintaining diesel generators.

As with other critical infrastructure, resilient power service providers are emerging to serve the cell tower market with retrofit solutions. One example is the Panasonic Eco Solutions Green Tower, unveiled this month at the Mobile World Congress in Barcelona. The company offers a plug-and-play product that marries a lithium ion battery to a small solar PV array. The product is offered in a variety of sizes to support tower loads from 50W to 3kW. In addition to resiliency benefits, the system offers tower operators increased energy efficiency, reduced operating costs and, in some markets, the opportunity to benefit from net metering and electricity arbitrage.

Panasonic’s solution is an energy-as-a-service model similar to the one companies like Solar Grid Storage (recently bought by SunEdison) have been touting for larger facilities. It requires little or no capital outlay on the part of the facility operator, pays for itself in lower costs and added value, and relies on market economics rather than government grants to support deployment. It’s a proven model, successfully employed by the solar industry, that is increasingly being adapted to solar+storage hybrid systems.

The combination of new solar+storage technology, emerging favorable grid services markets, and third-party service providers presents states and municipalities with a unique opportunity. Resiliency should now be a requirement in cell tower siting and permitting, and states and municipalities should seek ways to incentivize resilient power retrofits at existing towers.

Solar+Storage: What It Is, How It Works, and Why Your City Needs It

Author: Lewis Milford, Clean Energy Group | Project: Resilient Power Project

Energy-Storage-101-featuredThe emergence of solar power in the last decade has been impressive, with accelerating scale up and reduced costs. Following on that progress, a new combination of solar plus energy storage is likely to be the story of the coming decade. The battery storage options for solar are likely to make solar+storage the go-to technology for a range of different reasons, including resiliency, cost reductions, and better integration of solar into building systems and the grid.

But none of that will happen until people understand how this new technology hybrid works in practice. Toward that end, Clean Energy Group has written a new paper, Solar + Storage 101: An Introductory Guide to Resilient Solar Power Systems.

This is another in an ongoing series of reports produced by CEG’s Resilient Power Project. Its purpose is to provide a basic technical background and understanding of solar+storage systems. It is meant as a starting point for project developers, building owners, facility managers, and state and municipal planners to become familiar with solar+storage technologies, how they work, and what’s involved in getting a new project off the ground.

The guide first explores how a solar+storage system generally works and the basic layout of system configurations. It then takes a closer look at the components involved and necessary considerations for grid interconnection. The guide includes a checklist for cities or developers to assess whether solar+storage systems make sense for their buildings. The checklist helps a building owner look at the facility’s utility bill, critical loads and solar needs, and how installing a solar+storage system might help to protect the building’s occupants.

There is a growing need for this technology combination all over the country. Whether wildfires in the West, hurricanes in the East, ice storms in the North, tornadoes in the Plains and Midwest, or severe storms and flooding across the country, extreme weather is causing more numerous and costly power outages with each passing year.

This troubling reality has led federal, state, and local governments, as well as many business owners and facility managers, to the realization that there is a dire need for a more resilient, distributed approach to the current centralized U.S. power system.

Many organizations are beginning to explore the benefits of self-generation and more robust solutions for emergency backup power. Instead of relying solely on a centralized delivery system, where large, remote power plants are responsible for powering many thousands of customers and electricity delivery can be knocked offline by no more than a downed tree branch or unfortunate squirrel, individuals and organizations are beginning to take control of their own energy future.

The combination of  solar photovoltaics (PV) with battery storage (solar+storage) is poised to play a pivotal role in this shift towards energy empowerment and the ongoing transition to more distributed and resilient power systems.

Historically, diesel-powered generators have been considered the standard for supplying emergency power in the event of power outages. Unfortunately, this dependence on diesel generators has left many in the dark when power is needed most.

Because backup generators sit idle most of the time, inadequate maintenance and testing often lead to failure when disaster strikes. And, unlike renewable energy sources, the power provided by diesel generators is typically limited by the amount of fuel that can be stored on-site. This is especially true during extreme weather events, when obtaining additional fuel may be extremely difficult or impossible due to widespread lack of power and limited resource availability. Because of this, even if diesel generators do work properly in an emergency, they may become useless during an extended power outage.

With steadily dropping costs in both solar and energy storage technologies, solar+storage has emerged as an economically viable and more reliable choice for emergency power. Not only do solar+storage systems have the ability to provide power indefinitely when the grid is unavailable, they can also cut costs and generate revenue during the 99.9% of the time when the grid is functioning normally. In many cases, these savings and revenue streams can drastically reduce the payback period of an energy storage system.

While solar+storage may not be the perfect solution for every resilient power project, its versatility and scalability make it ideal for many facilities, especially those located in urban and residential environments where space may be at a premium. A number of facilities that provide crucial services in times of emergency are good candidates for solar+storage; the list includes schools, community centers, assisted living facilities, and multifamily housing units.

These buildings often have relatively modest critical loads that are well-suited for the technology. The needs of more advanced projects, such as business complexes and microgrids, can also be met by large-scale solar+storage applications.

Clean Energy Group has also released a companion report, What Cities Should Do: A Guide to Resilient Power Planning, which provides a series of guidelines and best practices for cities and towns preparing to deal with the impacts of severe weather events. For more information on these reports, and for other resilient power resources, please visit


This blog post was also published on Renewable Energy World.

Cities and Resilient Power: A Clean Energy Solution for Climate Adaptation

Author: Lewis Milford, Clean Energy Group | Project: Resilient Power Project

Resilient-Cities-featuredEvery city should have a resilient power plan for critical public and private facilities to keep the lights on, the communication systems running, and emergency services operational when the grid goes down. Most cities don’t, and that leaves millions of their most vulnerable residents at risk from the damaging effects of long-duration power outages.

Clean Energy Group’s report, What Cities Should Do: A Guide to Resilient Power Planning, describes a plan of action for cities to become more “power resilient” using new technologies like solar and battery storage, which can be more reliable than diesel generators to protect vulnerable populations from harm due to power outages caused by severe weather.

In addition, resilient power systems can provide power continuously as well as provide power protection when the grid goes down. Solar PV and energy storage (solar+storage) systems could also save money, generate revenue from ancillary services such as frequency regulation services and demand response, reduce peak load demand, and reduce reliance on fossil fuels.

Cities need to look at their critical facilities and decide how new, cleaner technologies can protect the elderly, the disabled, and the poor from the devastating effects of power outages. Clean Energy Group’s report includes planning guidelines for cities and towns that are preparing to deploy resilient power systems to lessen the impacts of severe weather events and other events that can disable the electric grid.

The report also describes how emerging technologies like solar+storage can provide cleaner and more reliable solutions available to protect community members in affordable housing, assisted living, schools, and emergency shelters.

In What Cities Should Do, Clean Energy Group says that cities should consider the following recommendations to implement a resilient power plan:

  • Assign a person or group in charge of the problem and implementing the plan
  • Identify the top list of critical facilities in need of power protection
  • Assess the critical power loads in each priority critical building/facility that need to be covered during a power outage
  • Determine the costs and technology options for each resilient power system, by looking at newer, clean energy options like solar+storage
  • Find an energy storage developer to design and build the project
  • Identify financing options to get the job done at least cost, including those that monetize new grid ancillary services that could significantly reduce the upfront capital costs of these projects.

Cities need better strategies and investment plans to protect their populations from power outages in severe weather events, and they can rely on new technologies like solar+storage to do so. What Cities Should Do is a valuable resource for state and city planners, project developers, building owners, and facility managers who would like to learn more about the vital role of resilient power in a city’s climate adaptation plan.

Clean Energy Group has also released a companion report, Solar+Storage 101: An Introductory Guide to Resilient Power Systems, available here.