How Could Solar+Storage Benefit Your Community? Find Out for Free.

Author: Seth Mullendore, Clean Energy Group | Project: Resilient Power Project

Sample results

A new release of the National Renewable Energy Laboratory’s (NREL) free online tool allows anyone to enter in a building’s information to estimate how much solar PV and battery storage (solar+storage) capacity would be needed to keep critical loads powered during an emergency.

The REopt™ Lite web tool is designed to assist users such as building owners, energy managers and community planners in:

  • evaluating the economic viability of grid-connected PV and battery storage at a site,
  • identifying system sizes and operational strategies to minimize energy costs, and
  • determining system sizes that can sustain critical loads through a specified outage period.

The tool’s newly enhanced features let users quickly evaluate the costs and benefits of a solar+storage system optimized to power essential services – like lighting, refrigeration, and communications – when the grid goes down. These expanded capabilities mark the first time that resilience and economic goals for installing solar+ storage can be compared and balanced within the same easy-to-use interface.

The tool allows users to evaluate solar+storage for any commercial building, including businesses, schools, public facilities, and multifamily housing. All that’s required to get started is some basic information about the building, like its location and electricity rates.

With this information, and the ability to add and fine-tune many other additional details, REopt Lite calculates and estimates the optimal solar+storage system sizing to meet two main design objectives:

  • Financial benefits. Though a number of tools can evaluate the economic benefits of solar, adding storage into the equation makes things much more complicated. For most commercial customers, the main economic benefit of adding battery storage is to reduce demand charges. Demand charges typically range anywhere from 30 to 70 percent of a monthly utility bill for commercial customers, from local community centers to giant data centers. Unlike solar and efficiency measures, batteries can directly target and manage periods of high electricity demand, resulting in significant customer savings. As an example, Walmart has been using battery storage to cut costs since 2013.
  • Resilience benefits. Meeting resiliency goals is also a concern to many building owners. Recent disasters in places such as Florida and Puerto Rico, where widespread outages contributed to devastating loss of life, have underscored how important it is to give building owners and emergency planners straightforward tools to evaluate how to make buildings more resilient. By installing solar+ storage, buildings can keep critical loads powered when the grid goes down. While it can be difficult to put a value on improved resilience, there is a clear benefit in allowing a business to stay open; enabling residents to shelter in place; and, in the case of facilities like medical clinics and emergency shelters, keeping equipment functioning to potentially prevent loss of life.

Instead of having to design a system for economics and resilience independently, REopt Lite now lets users evaluate these sometimes conflicting goals in a simple, side-by-side comparison. Users can start by designing a system that maximizes savings and then look at the resilience the system could provide, or start by meeting resilience goals and seeing where the economic gap may be.

The REopt Lite tool also gives users the ability to assign and adjust a value representing avoided outages. With this added feature, it’s possible to evaluate what the benefit of improved resilience may be worth to a building owner or community. Another new feature lets users incorporate existing on-site generation, like a diesel generator, into their resilient design evaluation.

These and other enhanced resilience capabilities were developed in collaboration with Clean Energy Group through its Resilient Power Project and supported with funding from The Kresge Foundation and the Department of Energy’s Federal Energy Management Program and Solar Energy Technologies Office.

On July 25th, Clean Energy Group will host a free webinar with NREL to walk through a real-world example of how the tool can be used to optimize and evaluate a resilient solar and battery storage installation. More information about the webinar can be found at


This blog post was also published in Renewable Energy World.

Oregon’s Renewable Energy Development Grant Program: Using Tax Credits to Leverage Private Investment

Author: Samantha Donalds, Clean Energy Group | Project: Clean Energy States Alliance

The Oregon Department of Energy’s (ODOE) Renewable Energy Development (RED) Grant Program uses a unique financing mechanism to promote investment in, and development of, renewable energy projects. By using a tax credit auction to fund the program, ODOE has provided competitive grants up to $250,000 for businesses, public bodies, schools, nonprofits, and tribes that install and operate a renewable energy system that produces electricity. Since 2012, ODOE has awarded nearly $5 million for 55 renewable projects statewide, including solar, hydropower, biogas, biomass, and geothermal installations. This innovative funding source – an independently administered auction of tax credits – has enabled the agency serve Oregonians without using scarce general fund dollars.

Oregon’s RED Grant Program, which started in 2011, is funded by the first-ever use of a state tax credit auction. This innovative financing mechanism combines the benefits of a direct grant program, where everyone can participate, with the benefits of the auction format, which encourages private investment in renewable energy. Other benefits of the tax credit auction are that it allows more revenue to be generated than the actual value of the tax credits, and the resulting proceeds from the tax credit auction can earn interest once deposited in the RED Grant Program subaccount.

During each round of auctions, Oregonians can bid on tax credit certificates in increments of $500; the minimum bid being $475. Buyers use the tax credits to reduce the amount they owe in state taxes. Additionally, buyers may be able to consider the tax credit purchase a charitable donation that they can deduct from their federal taxes, leading to bids in excess of the face value of the credit. The average bid from the most recent auction was $551.70 Besides the financial incentives to participate in the auction, many bidders are motivated by the opportunity to support renewable energy development in Oregon. Most of ODOE’s incentive programs have historically been in the form of tax credits.

Program Guidelines Support High-Quality Projects

The RED Grant Program supports renewable energy installations across the state – many of which would not be completed without the RED Grant Program funding. Through its intensive application requirements and review process, the program guidelines ensure variance among applicants so that a wide-range of projects can be funded.

To apply for a grant, project owners submit an application in response to an open opportunity announcement. Once submitted, the ODOE uses a two-tier system to ensure projects of the same size are compared against one another. Approximately $500,000 of the grant money will go to projects of up to 300 kilowatts. The remainder will go toward projects greater than 300 kilowatts.

The selected projects must start construction within 12 months of the execution of the performance agreement. During construction, the applicant makes periodic progress reports to ODOE. Each project’s performance agreement provides the timeframe to complete the project, usually two to three years.  Once projects are constructed and operating, project owners submit a final report documenting that the performance agreement has been satisfied. ODOE reviews the submitted material and conducts a site visit before dispersing grant funds. All projects issued a grant must remain in operation for at least five years to ensure that scarce funds are spent on long-sustaining projects. ODOE may inspect a project throughout the required five-year period of operation.

Projects are scored using several criteria, including amount of energy generated, resource diversity to support a variety of renewable types, and community benefits. Additional points are awarded for projects that achieve special public benefits, including: installations in rural communities and those with high unemployment rates; community-owned systems that benefit the larger community rather than just the building’s owner; and the number of jobs created and sustained by the project.

Since the RED Grant Program began, 35 projects – all solar installations – have been completed, totaling $2.2 million in grants. Twenty more projects totaling $2.8 million have been awarded tentative grants but have not yet been completed. Most of these projects are also for solar, but biogas, hydroelectric, and geothermal projects are also in progress. The $5 million in grant funding for the 55 projects is supporting nearly $75 million in total costs for the projects. In total, the RED Grant Program’s awarded projects – both small-scale and large-scale – are expected to generate approximately 103 million renewable kilowatt hours (kWh) each year, reducing carbon dioxide emissions by an estimated 156 million pounds annually.

In many cases, RED Grant Program-funded projects have helped awardees reduce electricity bills to zero and have influenced additional sustainability projects. For one project, at Coyote Trails School of Nature in Medford, the installed solar array has become part of the school’s teaching curriculum. ODOE has highlighted several RED projects and their benefits on ODOE’s blog and podcast:

In addition to providing funding, ODOE offers technical assistance and resources to entities exploring how to integrate renewable energy generation into their processes and/or footprint. These same resources are available to entities not seeking RED funding.

A Model for Other States

The RED Grant Program’s innovative funding mechanism can be replicated by other states and/or jurisdictions by those who allow the sale of tax credits. For states or jurisdictions that want to start slow, the RED Grant Program’s lower tier for smaller renewable energy generating projects is an intuitive start to supporting renewable energy generation, without having to commit large amounts of funding.

The Oregon Department of Energy was awarded a 2018 State Leadership in Clean Energy Award for the RED Grant Program. A report featuring detailed case studies on all of the winning programs will be published in late June, and will be posted at:


The Clean Energy States Alliance hosted a webinar highlighting Oregon’s RED Grant Program on July 11, 2018 – slides and a recording are available at:

PHOTO: Solar array at Bend Area Habitat for Humanity ReStore. This project was awarded $36,120 in RED Grant funds by the Oregon Department of Energy. Photo by Jennifer Kalez, Oregon Department of Energy.

Exemplary State Programs Continue Progress in Clean Energy with New Technologies and Markets

Author: Maria Blais Costello, Clean Energy Group | Project: Clean Energy States Alliance

This past year, the Clean Energy States Alliance (CESA) celebrated its 15th anniversary as a national, nonprofit consortium of states with robust, renewable energy programs. It is wonderful to see the impressive progress that CESA-member organizations have made to advance clean energy over that time. The collective impact of the states’ leadership and programs has been tremendous. In most parts of the country, and especially in states participating in CESA, the number of renewable energy installations has ramped up dramatically and clean energy deployment continues to grow. Both rooftop solar and utility-scale solar arrays are common sights; tens of thousands of wind turbines are churning out emission-free electricity; battery storage is in a period of rapid expansion; and various other clean energy technologies, including air-source heat pumps, wood pellet boilers, and biogas digesters, are gaining markets.

CESA’s State Leadership in Clean Energy Awards, established in 2008 and held biennially, highlight the continuing progress and achievements by state clean energy programs across the U.S. Past award winners have included state programs that supported the first Solarize program in the country and created thermal renewable energy certificates (RECs), as well as solar lease programs, commercial PACE, solar RECs, and business incubator programs, to name a few.

The 2018 award winners continue a tradition of innovation and practical solutions. The six winning programs have shown vision, perseverance, and creativity. They have helped establish new markets for offshore wind, energy storage, and solar financing. They also have stimulated community-level clean energy actions and made solar PV more accessible. The awardees illustrate the wide range of clean energy innovations that states are pursuing as they continue to transform clean energy markets.

The 2018 State Leadership in Clean Energy awardees are:

  • Connecticut Green Bank for its Solar for All Partnership, a ground-breaking public-private partnership between the Connecticut Green Bank and PosiGen Solar Solutions that offers a targeted solar lease paired with energy efficiency measures for low- to moderate-income (LMI) homeowners, regardless of income or traditional measures of creditworthiness.
  • Massachusetts Clean Energy Center (MassCEC) with the Massachusetts Department of Energy Resources for the Advancing Commonwealth Energy Storage (ACES) Program. This program was created to jump-start the energy storage industry in Massachusetts by piloting innovative, broadly replicable, energy storage demonstration projects with multiple value streams, thereby priming Massachusetts for increased commercialization and deployment.
  • New York State Energy Research and Development Authority (NYSERDA) for the Clean Energy Communities Program, which provides opportunities for local governments to earn recognition and grant funding by demonstrating their clean energy leadership. Since the program launched, over 400 communities across the state have completed more than 1,100 high-impact actions. These communities include more than 16 million New Yorkers, more than 80 percent of the state’s population.
  • Oregon Department of Energy for the Renewable Energy Development Grant Program. Since 2012, this competitive grant program has awarded nearly $5 million for 55 renewable projects statewide, including solar, hydropower, biogas, biomass, and geothermal installations. A two-tiered grant award system means similarly-sized projects compete against each other, allowing small projects to remain competitive.
  • Rhode Island Office of Energy Resources for its work to advance the Block Island Offshore Wind Farm, North America’s first offshore wind farm. This project represents a significant clean energy accomplishment for Rhode Island and the nation, and it is helping to spur an entirely new industry and job creator for the economy.
  • Xcel Energy Renewable Development Fund (RDF) for its support of the Minneapolis Park and Recreation Board (MPRB) Solar Demonstration Project. With funding from Xcel Energy RDF, the MPRB installed 200 kW of solar PV in the Minneapolis parks system to model the seamless incorporation of renewable energy into public amenities, which has resulted in the deployment of public-facing solar installations that reach not only millions of people, but also very diverse populations.

In July and August, CESA is hosting a free webinar series featuring each of the winning programs to provide additional information and lessons learned. The webinar schedule is noted below, with hyperlinks to the registration pages:

We invite you to learn more about the State Leadership in Clean Energy Award winners, past and present at, where an upcoming and past case study reports are posted and webinar recordings can be accessed.


This blog post was also published in Renewable Energy World.

Options for “Getting to Shore” Discussed at First U.S. Offshore Transmission Conference

Author: Val Stori, Clean Energy Group | Projects: Offshore Wind Accelerator Project, Northeast Wind Resource Center

Photographer: Jan Arne Wold / Woldcam. Courtesy of Statoil.

Offshore wind will be a major industry and economic opportunity for the U.S. Strong political leadership, pioneering state policies, and nearly 1500 MW of projects under development along the Atlantic coast are shaping the industry. Several states have made commitments to developing 8000 MW by 2030. One of the major challenges to realizing this industry is the development of offshore transmission and interconnection to onshore substations.

The opportunities and challenges of developing a cost effective, technically feasible, environmentally responsible offshore transmission network and interconnecting the offshore cables were the topics of the day at the first Offshore Wind Transmission, USA conference hosted by Global Transmission Report in New York last week. The availability and development of offshore wind’s associated transmission is a primary concern for investors and developers, and European experts and transmission operators were on hand to discuss their experience and its relevance to the U.S.

The conference sought to address three main questions: 1) what are the options for building the offshore transmission network; 2) what are the possible ownership models for the offshore transmission network; and 3) what technology solutions exist for the U.S.? Different sessions provided the state and federal policy context for offshore wind development in the U.S., explored the options for developing the transmission infrastructure, and discussed the technology and equipment needs in the state and federal regulatory context.

Two main schools of thought were presented at the conference—the “UK model” or the “generator lead line model” and the “German model” or “cooperative transmission model.” In the former, each project developer is responsible for building its own generator lead line to shore; before project operation, the transmission asset is sold to a transmission generator. By contrast, in the German model, the government mandated a physical extension of the grid into the North Sea to accommodate for future offshore wind development. The Transmission operator builds the grid and receives rate recovery. There are pros and cons to both in terms of cost effectiveness, environmental impacts, permitting timelines, shipping impacts, and construction lead times. The cooperative/shared transmission model likely has less environmental impact (limiting the number of cables to shore), can maximize value and reduce costs, and cooperatively approach the limited number of interconnection points. Conversely, shared infrastructure can strand built assets and lead to high costs. Such was Germany’s experience, where TenneT—the transmission service operator—had to indemnify several project developers for a delay in connecting completed offshore wind farms. Consequently, the shared infrastructure model poses greater risk.

In contrast to the German model, the UK offshore transmission ownership model allows a project developer to construct a direct radial/generator lead line to shore before selling the asset to an Offshore Transmission Owner (OFTO). This model may only be beneficial for the first tranche of projects, which can easily connect to the best available interconnection points. This approach also provides security of delivery, reduces risk, and provides a secure, strong revenue stream for the OFTO, which takes over the transmission line after construction. This approach, however, likely has greater environmental impact, can quickly block access to interconnection points, and can cause navigation/anchoring problems.

Developers at the conference voiced their preference for the direct radial approach versus the shared infrastructure approach so that they can have direct control over how and when the offshore transmission line gets built. One way to assuage developer’s apprehension of delayed transmission cabling is to cooperate on timing of a shared offshore infrastructure. Because the permitting and construction timing of an offshore project and a transmission network vary significantly, planning and permitting transmission routes needs to happen alongside—or in advance of—energy procurements.

In addition to hearing about the different models for getting offshore wind energy back to shore, conference participants learned about the different technology options for exporting the current to shore. Panelists discussed the applications for each technology and provided their perspectives on site-specific solutions to reduce capital costs and reduce line losses. High-voltage direct current (HVDC) is the current preferred method for exporting current to shore in Europe, as well as the common technology for shared infrastructure. However, in Europe the offshore wind farms are much more distant from shore and have greater installed capacity than the US will have from its first tranche of projects, and HVDC is better suited for long distances. HVDC is more expensive, but does result in fewer transmission losses. In contrast, alternating current (AC) has a shorter delivery time and can be a cheaper solution for exporting power. Its limitations include cable length and current and line losses.

Choosing the right grid solution and its accompanying technology can make a big difference to offshore wind costs. This conference was the start to a timely conversation on the heels of last week’s procurement announcements from Massachusetts and Rhode Island.


This blog was also published in Renewable Energy World.