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.

Written by Rick Peters

Solar is Booming in Washington DC

Washington DC has been a leader in solar development for many years.  In the last 12 years, DC legislators have set aggressive targets, helped to streamline solar permitting, introduced a solar access rights law, and passed a landmark community solar bill to increase access to solar for those without an available sunny rooftop.   Many of these policies include mechanisms to help bring the benefits of solar to communities of low and moderate income.  The collaboration between the solar industry and DC policymakers has helped to build a robust market where solar installations are happening throughout the city, from downtown office buildings to churches, warehouses and residential rooftops across the city.   These policies and the resulting private investments are creating good jobs in the District and reduced energy costs for many of its residents.

Double Down

Since solar and clean energy have been delivering in DC, the stakeholders decided they wanted a more ambitious goal.  In the summer of 2018 the District started on a path to double down with their commitment to renewable energy by proposing the most aggressive renewable energy target in the country when compared to other state policies.  The new goal calls for 100% clean energy (5.5% solar) by the year 2032, with 10% solar by 2041.  Hawaii and California are the only other states that have 100% goals, but both of those targets are positioned for 2045, quite a few years later than DC. 

Other Benefits of the legislation

In addition to doubling the renewable energy target, the proposed legislation would provide a few more benefits to solar advocates.  The bill:

  1. Limits geographic eligibility over time to concentrate the solar development in the District or on the District’s grid
  2. Pulls the current solar carve-out schedule forward by two years to increase SREC demand
  3. Extends the solar carve-out from 5.5% in 2032 to 10% by 2041
  4. Addresses specifics about previously contracted (“grandfathered”) load that is exempted from the newest RPS
  5. Includes transparency requirements on the energy suppliers to provide insight into the exempted load and associated time periods
  6. Modifies Alternative Compliance Payment (ACP) schedules to require $300 ACPs through 2041
  7. Increases the shelf-life of an SREC from three to five years, increasing SREC price liquidity and stability.
  8. Introduces various reporting requirements on the Public Service Commission in order to keep the Council and the Public apprised of the progress of renewable energy development.

We’re in the Home Stretch

The Clean Energy DC Omnibus Amendment Act of 2018 was introduced in July 2018 and made its way through the Council over the fall with hearings and two unanimous votes of support on November 27th and December 18th.  In January, the bill was submitted to Mayor Bowser for her signature and she obliged on January 18thClick here to read the bill“.   The remaining hurdle is for approval by the US Congress within 30 legislative days.  The only way that Congress can stop this legislation is with a joint resolution and the President’s signature.  As a result, passage into law is considered by most to be inevitable and in fact we are seeing market pricing for SRECs responding accordingly.

Thank your Legislators

So now that the law is almost passed, it is time to prepare to deliver.  The industry has a lot of solar to build and we’re working hard at that.  As a solar advocate who cares about renewable energy in DC, please consider taking a few moments to call or write to your Councilmember to thank them for their support of Clean Energy DC Omnibus Amendment Act of 2018.  It’s always important to show our gratitude.

Thank you for your support of solar!

Residential Solar Panels, Solar Service ,Home Solar Panels
Written by Anonymous

SES Selected as Installer for Solarize Frederick County Initiative

Residential Solar Panels ,Solar Service ,Home Solar PanelsFREDERICK, MD: Today SES was informed by the Frederick County’s Solarize Committee that they were chosen to be the official Solar Water Heater installer for the Solarize Frederick County initiative.

The pilot program aims to increase installations of solar water heaters, as well as solar electric (PV), systems in Frederick County County.  The financial incentives include County grants and volume purchase agreements, in addition to pre-existing state and federal grants.  Astrum Solar were selected as the solar electric (PV) installer.

While funds last, all Frederick County residents are eligible to apply for the incentives that reduce the cost of a solar water heater (or solar electric PV system) by up to 85%.

Solar Service, Home Solar Panels Washington DC Solar
Written by Rick Peters

SES Embraces SunPower Partnership

Many of our prospective customers have been waiting to buy their panels in the hopes of significant advancement. “I want the technology to mature ” they say, “ and be state-of-the-art”. Well, the closest you can get to those standards with a production panel is with SunPower.

Ask around, do some Google searches. You’ll learn quickly that SunPower is considered the best with very little debate. In fact, it’s by far the best. This American born company launched out of the US university research system (the founder was a Stanford professor) has sustained a 23 year run to be acquired recently by a global energy company.

At Solar Energy Services we’re excited to report that we are now a SunPower certified dealer. We’ve always wanted to offer the very best PV product and now we can. SES is proud to tie our 35 year commitment to the industry to the world leader in solar panel manufacturing.

Many are aware that the cost efficiency of installed solar has improved dramatically in the last 5 years due to efficiencies gained through price competition, distribution improvements, development of installation techniques, and other process improvements. However, the physical efficiency of solar cells has advanced more slowly than most have hoped. The standard Chinese panel being installed by the majority of installers today (especially the large leasing firms) are in the 14-15% efficiency range. A few solar manufacturers have been able to stay notably ahead of the pack. SunPower remains out front with their standard 327 W panel (E20) at 20% efficieny. Sunpower’s new “X” (E21) is 21% efficient! That’s right, over 40% more efficient than the average panel out there. The X begins to ship in April 2013 – next month.

SunPower’s Maxeon cells are the industry leader in reliability and durability also. They’ve had only180 defects out of 7 million panels. That’s right, 1 in 39000! The Maxeon cell has redundancy in contacts, accommodating wear from thermal expansion. It has backside contacts that provide increases collection on the sunny side. They are highly durable with the best impact resistance ratings. They are backed by a solid company with great support and a bright future.

To recap, the physical efficiency of solar cells has been relatively stagnant, with the exception of a few leaders that have developed slow and steady progress. SunPower has led the way. The company has been around for over 23 years. They have the most durable solar cell in the industry and the highest performing. I must confess, the 3 year old solar PV system on my roof has panels made in China. If I were installing today, there is no doubt I’d choose SunPower…

Written by Anonymous

Frederick County Detention Center to get Solar Heating

COUNTY DETENTION CENTER TO GET SOLAR HEATING

The Frederick County Adult Detention Center is going green as work has begun on the installation of a solar power array that officials hope will save the county money in the long run.

The roof-mounted system will be used to heat water for the jail, which Lt. Keith Welty, commander of fiscal services, said is one of the counties largest users of hot water…

Written by Anonymous

DC Condominium Community Installs Solar Water Heater

WASHINGTON, DC:  Solar Energy Services, Inc. installed and commissioned a solar thermal system at Tiber Island, a waterfront condomimium community in Washington, DC.

SES was contracted by Skyline Innovations, a third party solar developer, to design and install the solar water heating system that acts as a pre-heat to the facility’s natural gas water heating system.

The solar system consists of 76 solar arrays mounted to the building’s roof.  Each array has 30 evacuated tube collectors that are closed-loop plumbed to a 5,000 gallon solar storage tank.

The system is expected to offset a large portion of the facility’s conventional utility bill.

Written by Anonymous

Multiple Solar Thermal Installations on American University’s Campus

WASHINGTON, DC:  Earlier this week, Solar Energy Services, Inc. completed the installation of three separate solar water heating systems on the campus of American University…

 The Mary Graydon Center, which houses a dining hall as well as various administrative offices, was outfitted with a rooftop solar thermal collection system which included 16, 30-tube solar collectors.  These collectors are closed-loop, plumbed to 7, 120-gallon pressurized tanks for a total storage capacity of 8,406 gallons.

Anderson Hall, the largest of AU’s dormitories housing over 770 students, was outfitted with 81, 30-tube solar collectors closed-loop plumbed to a unpressurized 5,000 gallon storage tank.

Letts Hall, housing dormitories and a fitness center, was outfitted with 55, 30-tube solar collectors closed-loop plumbed to 1, 3,111 gallon storage tank.

All three solar water heating systems will serve as a pre-heat to the buildings existing conventional water heating systems.

Click HERE for post-installation pics

Written by Anonymous

Another Washington, DC Condo Building Installs a Solar Water Heater

WASHINGTON, DC:  Solar Energy Services, Inc. completed installation of a fully automatic solar water heating system at Park Tower, an apartment building located in the historic Adams Morgan neighborhood.

The building is home to 125 apartment units throughout its five floors.  SES was contracted by Skyline Innovations, a third party solar developer, to install and commission the solar thermal system.  It consists of 48 solar thermal panels and three 1000 gallon thermal storage tanks.  The system is slated to offset a huge portion of the building’s conventional water heating system.

Written by Anonymous

Washington, DC Condos Go Solar Thermal

WASHINGTON, DC:  Solar Energy Services, Inc. began work today on the installation of a solar water heating system at Webster House, a condominium complex in downtown Washington, DC.

The building houses 175 units on its 9 floors, and contracted with Skyline Innovations, a third party solar developer, to offset its large heating load with solar.  The building will be outfitted with 44 solar thermal collectors and a 3,111 gallon thermal storage tank.  The system promises to offset a huge portion of the building’s conventional water heating system.

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