Written by Lisa Walsh

Developer’s Success Story – A Solar Integrated Green Roof in NE DC

By Lisa Walsh | Commercial Solar Developer | Solar Energy Services, Inc.

For the newly-finished Taylor Street Storage facility in North East DC, a 17,500 square foot green roof with fully integrated solar panel array that showcase a value-stacked, elegant design providing both a cost-effective solution to storm-water management. All without forfeiting the solar panels that generate income via federal tax incentives and DC’s superb solar production-based financial incentives.


With over three million square feet of green roofs in Washington DC and 50MW+ of solar installations – the City is no stranger to either technology. However, the integration of both on the same roof is less common, despite the symbiotic relationship between the two offering a number of advantages.


Beds of Sedums awaiting Fall planting at Taylor Street Storage, Oct 2018.
Photo Credit – David Gorman of Lock 7 Development

Completed 133.980kW Solar-Integrated Green Roof at Taylor St NE WDC
Photo Credit – David Gorman of Lock 7 Development

Storm-water Management


Approval for a commercial building permit in Washington DC must include a storm-water management plan as defined by DC’s Department of Energy and the Environment (DOEE). For Taylor St, the Development team could have chosen between:

  1. Lost parking spaces to house costly underground containers for capturing and storing runoff
  2. Payment of ever-increasing storm-water management fees
  3. Implementation of a multi-layered Green Roof to treat 100% of the rainfall obligation with a perennial, sedum based plant surface – as per DOEE requirements.
    The green roof offered a cost-effective storm-water management solution that required no additions or demo’s to the existing structure.
    Solar Panels

Solar Panels

Most savvy developers realize that an empty roof in Washington DC is money left on the table. With the best solar financial incentives in the USA, the payback is rapid followed by years of production-based paydays. Small wonder that the development team at Taylor Street were interested if – and how – a solar array could integrate with a Green Roof. The good news is not only does the solar system seamlessly integrate with the green roof but the relationship is one of symbiosis and cost-effectiveness. Here’s why:

BALLAST. Most solar systems installed on DC’s commercial flat roof areas are ballasted. i.e. an assortment of concrete blocks, along with the weight of the solar panels and racking, is engineered to hold down the weight of the array with minimal or no penetrations to the roof membrane.
With close to 35 PSF of weight, a green roof more-than provides this ballast negating the need for concrete blocks or supplemental attachments. This is worth mentioning as the Green Roof is now a fully engineered component of the solar system bringing the question of tax credit eligibility into play. Is the Green Roof, or portion of, now eligible for the 30% Federal Tax Credit? Certainly worth conferring with a tax adviser.

A close up of the Solar System mounted into the soil on the roof.

CREATION OF A MICRO-CLIMATE: Furbish designs their perennially healthy green roofs with a wide palette of sedum species. These drought-resistant succulants require little maintenance and have varying requirements for daily sunlight – from full-sun to all-shade. Contrary to first impressions the intermittent shading and weather protection provided by the solar panels provide a micro-climate highly conducive to the plants underneath, in between and around the solar arrays.

DESIGN: Most ballasted solar systems have ample aisles between each row of solar panels insuring that each solar panel is optimized and avoiding shading from the panel row in front. Solar panels can also be tilted anywhere between 5 and 35 degrees. This is adjusted to account for shading, panel count and orientation considerations. This flexibility of design was helpful for integration the green roof. Aisle spacing, solar panel size and tilt were designed with the Green roof in mind – not only as it relates to healthy plants, but also for annual maintenance access requirements.

Established Example featuring similar product and design as Taylor Street


CHALLENGES: Solar-integrated green roofs are not as common as their singular counterparts. Fair to say this project did not come without some challenges


DOEE DESIGN STANDARDS: Department of Energy and Environment is responsible for DC’s Stormwater Management and insuring all DC buildings comply with runoff standards. The burden was on SES and Furbish to ensure that the solar arrays were not going to impede the ability of the plants to thrive and provide the necessary water retention requirements. The design and permitting side of the project insofar as panel tilt, aisle spacing and racking integration were designed in collaboration with DOEE.


INSTALLATION TIMELINES: Furbish Company are Green Roof specialist, Solar Energy Services, Inc. are solar specialists. Integrating these technologies took heightened coordination between our installation teams, mostly in terms of labor efficiency, communication and timeliness. The latter was particularly stringent as the Certificate of Occupancy, required to meet the developer’s lease requirements, was contingent upon the completion of the Green Roof which now included solar racking, wiring and panel installations. Throw in some PEPCO Permission to Install challenges related to the solar portion, and the pressure was on.


The project came with some unusual PEPCO interconnection timing challenges at the end. Ironically not related to the Green Roof aspect of the application. Nonetheless, this system is now outputting electricity like gangbusters. All’s well that’s ends well.

Written by Rick Peters

Maryland Solar – Ready to Grow Again

For many years, Maryland has been a leader in solar policy and solar deployment.  In the last 3 years, we’ve fallen behind other states, watching our robust growth give way to several years of decline.  It’s almost hard to believe, but Maryland has been losing solar jobs for more than two years after peaking at approximately 5300 in late 2016.

Policy Clouds

Why is this happening?  One of the biggest reasons is the value of the state solar production incentive, the SREC (Solar Renewable Energy Certificate).  Those of you who own solar or have considered buying solar are probably all too familiar with SREC pricing.  Because Maryland property owners adopted so much solar in the first half of the decade, we outpaced the state’s goals, depressing the value of the market-based SREC incentive.  This was a good problem for the industry to have until it became clear that our goal (25% renewables by 2025 with 2.5% solar by 2022) was clearly not aggressive enough.

The Time is Now

We are now at a time of severe urgency for the Maryland solar industry.  With installations on the decline for over two years and job losses mounting, we are losing a trained employment base and leaving federal tax benefits on the table.   The solar industry has been working with other coalition members (wind industry, environmental organizations, etc.) for a few years to try to increase the state’s Renewable Portfolio Standard (RPS), but have been hampered by the Hogan Administration’s reluctance to incentivize more renewables until the completed RPS Study Report is released.  The study was due to be released in December of 2018, but has been delayed and some fear this is intended to stall an RPS increase for another year.  We cannot wait.

Governor Hogan has gone on record with his desire to fight climate change.  He recently coauthored an OpEd in the Washington Post with Virginia’s Democratic Governor, Ralph Northam to emphasize the urgency and the need for bipartisan solutions to climate change.  It is in this bipartisan spirit that we hope to see the Hogan Administration support the Maryland General Assembly in passing the Clean Energy Jobs Act
(CEJA)(SB0516, HB1158) of 2019 that will increase our renewable energy goal to 50% and the solar portion to 14.7 %. “Click here to read more about this

No-Brainer Investment for Maryland

One of the primary arguments against increasing the RPS has to do with the impact on utility ratepayers.  The preliminary indication is that the increased renewable goals associated with the CEJA will add approximately $1.85/mo. to the average electricity bill.  While this is not insignificant, it is important to note that a 2018 Daymark study, commissioned by the Hogan Administration’s Public Service Commission, found that for every $1.00 of investment in solar, we return approximately $5.00 in economic and health benefits to the state.   Solar jobs are good jobs that pay well, representing a path to economic stability for many installers.  And best of all, solar installation jobs cannot be exported.

We need YOUR help

As a solar advocate, we ask that you commit to express your support for CEJA in the Maryland legislative session this year.  The bill has been submitted and we should have a bill number shortly.  In the meantime, please continue to advocate for more solar whenever you can and be prepared to contact your Maryland state legislators to support this important legislation when the time comes.  Stay tuned for a special email notification with the bill number, and suggested talking points in the coming weeks.

Home Solar Panels,Eastern Shore MD
Written by Rick Peters

Solar Energy Trends

Some Positive Trends:

Eastern Shore MD,Residential Solar PanelsThe Challenges:

Industry consolidation can be disruptive

Residential solar leasing is fast outpacing cash sales in many of the more developed states, like Maryland. It’s what many Americans want so it will continue to drive the market. It seems to work for more of America.   After all, we do like instant gratification and if I can save $10/month immediately, and feel good about it, where do I sign? While SES is typically strongly advocates for cash sales to our customers who are able, no one can argue the enormous impact and value that the various residential and commercial financing options have delivered. Getting solar access to the mainstream will be the most critical piece to advancing the development of distributed solar. It really has been transformational so far.

There’s other good news. System Pricing, though leveling off somewhat, has dropped dramatically in the past 5 years. While incentives decline as planned, the industry continues to drive down installation costs to maintain the impressive paybacks and internal rates of return.

Beneficiaries of solar price reductions include states like Maryland, who had the foresight to seed this industry over the last 6 years. Government and industry partnership in Maryland has built an economic environment that supports solar development and as a result, it is sustaining 2200 jobs while Maryland continues to meet its solar RPS goals. That’s right, our industry delivers over 2200 paychecks in Maryland. In fact, there is now a solar thermal equipment manufacturer in Baltimore. Much to be pleased about.

There’s also a darker side. Bankruptcies and consolidation of solar companies have carried the headlines quite a bit in the last year especially. While a natural part of the tech/business evolution cycle, consolidation and shake out are always disruptive, not only to industry members, but also to consumers of these solar energy products and services. As a result, all of the solar “investors” are asking lots more good questions – particularly about the longevity of the manufacturer and the installer. Popular questions, particularly in the solar PV panel world, are “Who will be here to support my warranty?” and “What is the design track record of these systems?”

The beneficiaries of these trends will be those with a proven commitment to the industry either through time or capital. It’s that commitment that gives customers confidence of future support if and when it is needed. Whether it’s an installer with 35 years experience or a manufacturer like SunPower that has 25 years in business, longevity is a key indicator of future availability to support the install base.

Written by Anonymous

Solar Water Heating for a Multi-Family Housing Complex

WASHINGTON, DC:  3501 13th St. NW is the latest address to have a solar thermal system installed.  The multi-family housing unit now has solar collectors on the roof, installed by Maryland solar contractor Solar Energy Services, Inc. to pre-heat the building’s existing conventional water heater.

The solar system includes 32 solar thermal collectors, south-facing on the building’s roof, closed-loop plumbed to 2, 806 gallon tanks.  The system is expected to significantly reduce the building’s utility bill by offsetting their water heating load with solar.

Written by Taryn Faulkner

University of Maryland Solar Electric and Solar Water Heating

COLLEGE PARK, MD:  Solar Energy Services, Inc. completed the installation of a 5 kW solar photovoltaic system at UMD’s Cole Field House at the College Park Campus.

The system consists of 30, 175-watt SolarWorld panels and a Sunnyboy string inverter.

On the same campus, at the Ellicott Dining Hall, SES also completed installation of a solar water heating system that will act as a pre-heat to the dining hall’s existing conventional system.  This system consists of 20, 4′ x 10′ flat plate AET thermal panels on the roof, closed-loop plumbed to three 120-gallon Vaughn Solar Sepco tanks.

See Post-Install Pics of Colefield House PV System

See Post-Install Pics of Ellicott Dining Hall