Solar Service ,Home Solar Panels
Written by Lisa Walsh

DC Property Owners: Big Hot Water load = Big Solar Incentives

Commercial Solar Service, Annapolis MD

A growing number of building owners, developers and condo associations in the District of Columbia have come to realize that their building happens to be located in the most solar-friendly city in the USA .  Solar contractors, investors and financing vehicles are falling over each other to get solar panels on District roofs and start generating  the lucrative solar renewable energy credits (SRECs).   Whether via Direct Purchase, or $0 solar leases – SRECs are undoubtedly the reason for the solar season in DC (more to follow on those below).

However, before you sign on the dotted line and fill your roof with a 25-year solar PV (electric) system, as offered by 9 out of 10 solar professionals, make sure that you’re not losing the opportunity to vastly increase your return on investment with a Solar Thermal System.

Solar Water Heating Feasibility

The pre-qualification for a Solar Thermal System involves three questions:

  1. Does your building have a substantial, daily (365 day) hot water need? (i.e. apartment building/condos, restaurant, laundry, brewery, health center)
  2. Does your building have a centralized water heating system (as opposed to individual units throughout the building)?
  3. Can the building accommodate additional storage tanks?

If you answered YES to these three questions you really (really) should first consider a Solar Water Heating system either before – or at a minimum – in tandem with, a solar PV system.  (Shopper Beware – unless your solar contact has experience with solar thermal – which many do not – you’re going to have to be prepared to shop further).

What is Solar Water Heating (or Solar Thermal)?

Other than using the sun for energy generation, Solar Water Heating Systems operate entirely differently from their electron-shaking PV counterparts.  These time-tested, technologically mature systems are mechanical in nature and relatively simple.

Moreover, a solar thermal panel is 60 – 70% efficient; whereas a solar PV (electric) panel is typically 17 – 24% efficient.  Therefore, solar thermal panels generate substantially more energy per square foot than PV panels,  monetizing many more SRECs.

Solar Service , Home Solar Panels, Solar Renewable Energy

 

Let’s Review SRECs…

SRECs (Solar Renewable Energy Credits) – along with the 30% Federal Tax Credit and 100% Year 1 depreciation– are what drive the tremendous economic benefits of solar in Washington DC; one of several jurisdictions that have enacted a Renewable Portfolio Standard requiring that a specific percentage of electricity consumed must come from solar.   Whether residential, commercial, or institutional, each time a solar system generates 1 Megawatt hour of energy – the solar system owner generates 1 SREC.  This SREC is then sold via aggregators to an SREC market where it is bought by competitive energy suppliers to allow them to meet their share of the compliance obligation, or else pay a legislated fine (Alternative Compliance Payment, or ACP) for every SREC they are short.  Washington DC currently generates the highest SREC values in the country, largely due to the fact that DC does not have the real estate to install large solar farms which can rapidly oversupply a market and drive down SREC prices.

How much are SRECs Worth?

Washington DC SRECs are currently trading at $395/SREC.  To provide a frame of reference, a 6000 sq ft rooftop in Washington DC outfitted with a 75kW solar PV (electric) system could generate around 90 SRECs/year (over $35,000/year).   Depending on variables such as system size, corporate tax rate and and project site attributes, this SREC income – combined with a 30% Federal Tax Credit and 100% Year 1 depreciation, typically result in IRR’s between 30% – 60% and a Simple payback of 3 – 5 years.    Assuming solar thermal is applicable, this same roof outfitted with a Solar Thermal System could fit a kWh equivalent of a 150kW+ system, generating 180 SRECs/year – and see an IRR of 50 – 80%, with a simple payback in the 1 – 2 year range.

Solar Service ,Home Solar Panels, Residential Solar PanelsMaintenance

Although Solar PV (electric) clients often opt for an O & M (operations and maintenance) contract through their solar installer, Solar PV Systems  have relatively minor maintenance needs; usually an annual inspection along with ongoing monitoring.    Solar thermal (water heating) requires a little more maintenance including a 3 – 5 yearly service which, at a minimum, includes a replacement of the propylene glycol/energy transfer fluid that can degrade with time.  Nonetheless, the impact of service costs on the overall IRR is relatively small and easily absorbed by the increased SREC income.

Written by Anonymous

Offset Your Oil-Guzzling Water Heater with Solar!

Offset Those Oil-Fired Water Heaters with SOLAR

Why oil-fired water heaters?  In many parts of the country there are no local gas lines for residential distribution.   In the Chesapeake Bay region where we operate, this issue is very common in the many river communities that are close to our world famous estuary.  The reason for this is primarily because there are so many peninsulas that don’t offer the high density to justify pipeline expenses.  In these areas, customers are forced to use other fuels like electricity, propane, and oil to heat their homes and domestic hot water.  This article will focus on the oil-fired boilers that are common in this region as well as in the Northeast US.

Cost of Gas Alternatives:  Many homes have heating boilers that run on fuel oil.  These boilers have tremendous heating power and can recover loads quickly.  They also tend to be relatively inefficient, dirty, and expensive to run.  Many of these boilers also have an on-demand water heating feature that adequately satisfies the household’s water heating load without the need for a standby tank.  This all sounds great except the price of home heating oil continues to climb with recent prices around $4/gallon on in our area.  To put that in perspective, the equivalent price for natural gas on an energy density basis would be about $1.00/gallon.  When oil users are paying 4 times the rate of those who have access to natural gas, they can hardly afford to be wasteful in how they operate their boilers.

Summertime Blues:  Here’s the dirty little secret about that on-demand oil-fired water heater on your boiler.  It is typically programmed to keep that big hunk of metal hot, all summer, waiting for you to call for hot water.  So a premium for your oil (compared to gas) is not the only thing you are paying for.  During summertime your air conditioner is competing with your heat-radiating oil-fired water heater.   So, here’s the way I – a not-so-proud owner of an oil heater – circumnavigated this issue:

My Solution:  I have solar photovoltaic (PV) on my home, but when I got into the solar business in 2008 the first thing I did was deploy solar water heating in my family’s home which allowed me to shut down our boiler for about half the year.  We also did some other control modifications for efficiency.  The first simple control is used to automatically reduce the boiler target temperature as the outside air temperature increases – for example, you don’t need 180 degree water to heat the house when its only 50 degrees outside.  Secondly, we converted the boiler to “cold start”, so it no longer wastefully heats on standby when we have a big tank of solar-heated water waiting to be used.  My family’s solar thermal system is slightly oversized (there are 3 forty square foot panels instead of 2) so that it could be integrated with our hydronic space heating system to give us a little space heating help from the sun.  [See our recent blog on combi-systems (hyperlink)].

So that’s the good news.  The GREAT news is that there has been absolutely no convenience impact on how we use hot water or space heating.  The system has saved us about $800/year in oil       expenses, the majority from offsetting our inefficient water heating, and the remainder from space heating.

Furthermore, the solar heating system is optimized in the summertime, all-but-negating the use of the oil-fired water heater.  The air conditioner has to work far less without having that heat-radiating boiler inside the home – like most are.

People are learning that different homes and circumstances often can benefit substantially more than others when you consider various renewable or energy efficiency technologies.  Oil fired water heaters are some of the sweetest low hanging fruit in solar.  In fact, I joke with my residential oil supplier that we should team up so he can get out in front of this trend that is eating into his oil sales.  He said, “no thanks – I’ll ride this as long as I can”.

If you forgot to make a new year’s resolution this year and you heat your home and your water with oil, then plant your flag!  If you’ve got some solar exposure, you must commit to get a free solar thermal assessment in 2014 and stop pouring money and finite resources down the drain.

Written by Lisa Walsh

Supercharge your Solar Water Heater

Solar Thermal not Solar PV: When talking about solar and space heating, it’s worth mentioning that the panels used for this type of solar application are not the same panels that power a house, a light, or any other electrically powered appliance. In fact, the only similarity between a PV (photovoltaic/electric) solar panel and a Thermal Solar Panel is that they both absorb solar energy. However, how each panels processes and distributes that energy is entirely different.

Enlarged Domestic Hot Water System: In order to make a solar space heating system cost-effective, most space heating systems are designed to include the home’s domestic hot water supply – thereby offsetting the gas/oil/electric bill and returning the solar system’s investment. Therefore, any space heating system is basically an enlarged solar water heating system. These systems that combine solar water heating and space heating are often referred to as combisystems. This combination is achieved with a solar storage tank that comes equipped with two separate heat exchangers; one for the domestic hot water loop and one for the space heating loop. The cooler water returning from the heating system passes through the upper heat exchanger on it’s way back to the boiler where it does one of two things: It picks up some heat that was generated by the solar system or, if the tank is cooler than the returning water, acts as a buffer tank allowing the boiler to have fewer on / off cycles thereby making it more efficient.

Space Heating Infrastructure: Radiant floor heating systems are highly compatible with solar thermal energy. This is mainly because these systems are designed to operate at low temperatures and thus the solar system can contribute energy more of the time. Hot water baseboards, radiators and other hydronic heaters can also benefit, especially if an outdoor reset control is installed. The outdoor reset control adjusts the boiler’s target temperature according to the outdoor temperature.
Forced air systems can also be modified to accommodate solar by placing a fan coil inside the existing duct work. A controller senses when the fan needs to be activated and, again, a conventional back up system kicks on as needed.

Heat Dissipation in the Summer: Of course here in Maryland/Washington DC,  in our Mid-Atlantic climate, solar energy for space heating is being summoned at a time of year when insolation (sunshine) levels are much lower than the rest of the year. Therefore more solar panels are required to meet the quota. A family of four would realistically need two, 4′ x 8′ flat plate collectors for their home’s hot water supply. Depending on the required space heating square footage, this collector size may be increased anywhere between 30 – 100%. To avoid overheating in the summertime when space heating is no longer required, there needs to be a mechanism to dispose of the excess heat. This can usually be achieved with anti-stagnation functions on the controller or by installing a heat dissipater on the roof. An ideal situation is to redirect this excess heat to a pool or hot tub, thereby creating a year round triple-application system that provides the largest return on investment.

Washington DC Solar Commercial Solar Service
Written by Rick Peters

Commercial Solar Water Heating: ANOTHER Renaissance?

Washington DC Solar ,Commercial Solar ServiceSolar water heating has quite a long history. In the United States alone, the industry has boomed and busted 3 times in the last 130 years – each time displaced by cheap energy. Many are surprised to know that the first US patent for a residential solar water heater was issued in 1891 to Clarence Kemp, a Baltimore inventor. That’s right, 1891.  In the 1920’s, 30% of the homes in Pasadena, CA had solar water heaters.  With the discovery of natural gas resources in the region, the industry evaporated almost overnight.  Solar thermal technology is mature and efficient; the problem lies with allowing our commitment to solar to dissolve in favor of decreasing natural gas prices.

In these previous industry “busts”, energy became cheap and we were lulled into a false expectation of stable prices. Each time, not long after the industry was dismantled, energy prices began to creep back up, making us long for that clean and cheap solar energy again. So today Solar Water Heating is on the rise again. Will it be different in the 21st century or are we doomed to repeat the same cycle? What was it that Winston Churchill said about failing to learn from history….?

The recent surge in US solar water heating deployments began in 2008. This resurgence, especially at the commercial scale, has helped to drive up adoption rates while scaling down installation costs. Several factors are converging in recent years to bring about this renaissance:

  • Engineers, architects, and contractors are becoming increasingly familiar with this mature technology – improving costs with increasing experience
  • Regional incentives are bolstering the existing federal incentives to reduce the capital investment.
  • The federal government has mandated that a minimum of 30% of water heating must come from solar for new construction or major renovations on federal buildings.
  • Project Developers like Skyline Innovations (http://www.nextility.com/) have introduced new business models to help deploy these systems for those without available capital.
  • Property owners increasingly want to have more control over their energy budget
  • Various societal pressures continue to reward solar adoption
  • An improving economy has allowed property owners finally to reinvest in their buildings

Remarkably, much of this has occurred despite a backdrop of rapidly falling natural gas prices (the primary heating fuel for commercial water heating), decreasing drastically from 2008 to 2012. However, in the last 18 months, natural gas prices are climbing again in a trend that is likely to continue: gas exportation; deployment of energy intensive manufacturing in the US; diversion of more natural gas to transportation (locomotives, trucks, fleet vehicles and eventually automobiles); conversion of more power plants and residential heating to natural gas.In light of these trends, property owners are rapidly moving forward to install solar water heating systems before the financial incentives expire. Business owners with substantial hot water loads in Washington DC and Maryland are able to achieve simple ROIs of 2-7 years. This approach requires them to take a slightly longer perspective, recognizing that they are buying 30+ years of energy up front for a fixed price (with generous subsidies). Whether financed independently or through the bank, building owners are able to lock in their energy prices and hedge the inevitable increase in fuel costs while leveraging all of the other benefits of renewable energy.

If you have any doubts about this trend, visit our commercial solar water heating page and take a look at the photos of just a subset of the projects we’ve been deploying in the region (https://solarsaves.net/commercial-solar-water-heating/).

If you want to know more about the history of solar water heating, check out this excellent book: The Golden Thread: 2500 Years of Solar Architecture and Technology, coauthored by Ken Butti and John Perlin.

Commercial Solar Service,Residential Solar Panels
Written by Anonymous

Commercial Solar Water Heating on the Rise

Residential Solar Panels,Commercial Solar ServiceWhile still a relatively well kept secret among the general public, large scale solar water heating is popping up in more and more places. While this technology is relatively mature, the practical deployment is still in its infancy.

While we’ve seen lots of growth in recent years, what is holding back solar water heating? Three things actually: Awareness, Cheap natural gas, and Inertia.

We’re overcoming the awareness challenge slowly but surely. Every week there is another article in the trade press about a prison, dormitory, military barracks, restaurant or health care facility adopting this valuable technology. These systems are piquing the interest of facilities managers, engineers, and architects on the demand side and mechanical contractors and manufacturers on the supply side; helping to raise awareness among the traditional commercial water heating business community. This is particularly the case in markets like Washington DC, Maryland, North Carolina, Nevada, and California where solar water heating systems benefit from the existing solar PV incentive markets.

Cheap natural gas. I’ve written on this before, but it’s worth repeating. Today’s wholesale natural gas prices are close to a ten year low, and more than 75% below their most recent peak in July of 2008. Recent data indicates that prices are trending up again, but the current low price combined with economic uncertainty has facility managers and CFOs hesitating until they can see a faster payback on a solar water heating investment. While a 4 year payback may not seem enticing in today’s economy, the problem with waiting for the inevitable price increase of natural gas is that you forgo some of the best incentives existing today that will surely be lower or absent in the future. Remember, the solar fuel is free in the future, so increasing gas prices will only improve the economic return in the future.

Inertia is one of the most powerful social forces I know. It plays a huge role here. As engineers and architects continue to gain experience and confidence in specifying SWH systems, volume will continue to drive down costs in much the same way that we have seen with solar PV. The federal government has required the use of SWH on all of their new construction, if feasible. The number of contractors who are capable of installing and servicing these systems continues to increase, giving prospective system owners’ confidence that the systems will not be supported in the future.

Below are a few links highlighting some commercial systems recently commissioned in the U.S. Read on and learn how commonplace this simple technology is becoming.

Written by Anonymous

DC Apartments Go Solar Thermal

WASHINGTON, DC:  The installation of a solar water heating system was completed today at an apartment building on Tunlaw Road in downtown Washington, DC.

The solar thermal system was designed and installed by Solar Energy Services, Inc., a Maryland- based solar installer, in partnership with Skyline Innovations, a DC-based third party solar developer.

The system includes 58 flat plate solar thermal collectors, a 3,200 gallon solar storage tank, and a 200 gallon buffer tank.  It is expected to greatly offset the building’s natural gas water heating system.

Written by Anonymous

Baltimore Business Thermal SRECs

Maryland Solar Water Heating Bill Moves Forward

The House of Delegates voted 132-5 Saturday, following the Senate’s unanimous 47-0 vote March 17.

The legislation would allow owners of solar water-heating systems to sell renewable energy credits. The credits are bought by utilities and power companies that need to meet government quotas of renewable energy generation; if they can’t generate enough green power on their own, they can buy credits from someone else who has.

The ability to generate credits via solar water heating makes those systems a more attractive investment and rewards the buyers for using less fossil fuel. That is expected to be a boon for the green power industry, seen as a growing source of new jobs.

Gov. Martin O’Malley pitched the legislation along with dozens of lawmakers as co-sponsors. House and Senate versions of the bill still must be passed by the opposite chamber, which is expected since the two bills are identical. O’Malley is then expected to sign off.

Written by Rick Peters

SES Letter to The Capital

Your recent editorial (The Capital, April 18) suggested Gov. O’Malley should put more emphasis on the distributed approach to renewable energy, where solar and wind power are generated by smaller systems throughout the state. In fact, the governor intends to sign legislation next month to do just that. Delegate Sally Jameson and state Senator Robert Garagiola sponsored what is essentially budget-neutral legislation (HB/933/SB717) to open up the state’s solar goals to include solar water heating, a very mature and efficient technology, first patented in Baltimore in 1891.

This family friendly technology currently saves a typical family of four about $500 per year on electric bills by obtaining 75 percent of their annual water heating energy from solar. The new law will allow system owners to sell green credits to help utilities comply with the state’s solar goals. Consequently, homeowners will now see simple paybacks on these affordable systems shortened from five to eight years to a very manageable two to four years, on a 25-year lifespan.

Aside from advancing our solar goals, and allowing modest-income homeowners to participate in the benefits of solar, there are significant economic benefits too. Solar water heating is a labor intensive installation, which keeps dollars recirculating in the community. It requires trades people to install it, a group much in need of work.

The components are low tech, but heavy and bulky , so there is strong incentives to manufacture domestically, if not locally. A typical residential system only requires 40 to 80 square feet of sunny roof, drastically increasing the potential pool of participants.

As a daily consumer of solar-heated water himself, O’Malley is well aware of the opportunity for Maryland. I commend him and our legislators for their leadership on this issue.

Written by Anonymous

Downtown Apartments Use Solar Energy For Water Heating

WASHINGTON, DC:  Installation of a 14 panel solar thermal system was completed at an apartment complex in historic Adams Morgan earlier this week.

Solar Energy Services, Inc., a Maryland based solar contractor, was engaged by Skyline Innovations to design and install the solar water heating system that will act as a pre-heat to the 33 units that use the building’s conventional heating system.

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.

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