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.

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,Commercial Solar Energy
Written by Lisa Walsh

Annapolis Restaurant Harry Browne’s Installs Solar Water Heater

Commercial Solar Energy,Solar ServiceSlowly but surely the skyline on Annapolis’ State Circle is starting to change. First, the Governor’s Mansion in 2009 and just this month, the ever-popular Harry Browne’s Restaurant (http://www.harrybrownes.com) has joined the ranks of businesses jumping on the solar bandwagon. Not only an enthusiastic and self-professed carbon footprint reducer, Rusty Romo, Harry Browne’s owner since 1979, is a savvy businessman, “Although I have a vested interest in reducing my carbon footprint, there’s no question that the solid Return on Investment was the final straw in deciding to install a solar water heater.” This viewpoint extends throughout Rusty’s business dealings, particular with regards to his restaurant’s waste production. Prior to January of 2012, annual trash pick up was costing the restaurant around $13,000 per year. That cost has now been reduced to $4000 due to Rusty’s implementation of two recycling solutions: 1) Veterans Composting visits several times per week to pick up all of the restaurant’s food waste turning it into compost for farmers, gardeners and landscapers. 2) A Cardboard baler compresses all of the restaurant’s cardboard, hugely reducing the bulk for taking to a dumpster storage facility where it is pulled and weighed. Harry Browne’s averages at least two tons every twenty eight days. Depending on the market cost, cardboard reclamation pays him from $30 – $100 per ton. Restaurants have a large hot water load, and Harry Browne’s is no exception. The 250-seat restaurant easily consumes the 160 gallons of hot water per day provided by the solar water heating system installed by Millersville based Solar Energy Services, Inc. (solarsaves.net) The system includes two, 30-tube solar collectors, (approved by the Historic Commission), mounted on a flat roof in the back of the restaurant. These panels are joined, via a copper pipe run and pump control unit to two, 80g stone-lined water tanks in the basement. The solar system acts as a pre-heat to Harry Browne’s conventional gas system, offsetting around 50% of his annual hot water load.

ABOUT SOLAR WATER HEATERS and SES, Inc.

Solar water heaters are a time-tested, mature technology that are deployed every day by Solar Energy Services, Inc. (SES) of Millersville (solarsaves.net). In addition to restaurants, apartment buildings, universities, carwashes, detention centers and other government and institutional buildings continue to expand SES’s customer list. Roger Perry, a 35-year solar veteran and partner at Solar Energy Services, Inc., is still servicing solar water heating systems that he installed during the early eighties. Roger notes that “Given current financial incentives, solar water heaters are a no-brainer for any business in MD and DC that has a daily hot water load.”

Commercial Solar Energy, Solar Energy Services
Written by Anonymous

Assisted Living Complex Installs Solar Water Heater

Commercial Solar Energy, Solar Energy ServicesGLEN BURNIE, MD:  Glen Square, a senior assisted-living complex in the heart of Glen Burnie, MD now have a solar water heating system that will offset a large portion of their natural gas water heating system.

The solar system is financed by Skyline Innovations, Inc., a Washington, DC based third party solar developer, who engaged Solar Energy Services of Millersville, MD to design and install the 42 panel solar thermal system.

Commercial Solar Energy Residential Solar Panels
Written by Roger Perry

Would that be One Tank or Two, madam?

Solar veteran Roger Perry discusses the pros and cons of One Tank Vs Two for Solar Back-up

Commercial Solar Energy ,Residential Solar PanelsAll solar water heaters in Maryland, D.C. and the mid-atlantic provide a family of four with around 75% of their annual hot water load. Most customers use their existing electric or gas sources for the remaining 25% backup (usually needed dead winter). When installing a solar system one question that will come up is “Should I use my existing tank and have it fed by the solar system?” or “Should I remove my existing tank and use the electric back-up that comes in the solar tank?”. A couple of situations make this an easy decision;

  1. An existing electric water heater with no room for another tank. This is especially satisfying and cost effective if the existing tank is leaking or on it’s last legs. It’s like getting $1500 off the cost of a solar system because that money would have needed to be spent anyway. In this case you would definitely chose a single tank system.
  2. The other is if you have a gas water heater. While not as cut and dry as the example above, using the electric element would mean using a higher cost fuel for back-up (not so much with propane). Much of this extra cost would be mitigated because the single tank back-up would not run as much because it would be affected by solar input without running a faucet. You would need to run an electric circuit (30 amp, double pole breaker). This may be difficult or very easy depending on the breaker box location and available space in it. Most jurisdictions will also require a master electrician and a permit for this to be done. In this case, I think, most people would shy away from a single tank system unless there was just no room for another tank.

Let’s look at the pros and cons of each system;

SINGLE TANK PROS

  • Smaller footprint
  • Less heat loss
  • Electric element can sense the solar output and not come on from stand-by losses
  • Can go “all solar” just by turning off the element (essentially flipping a switch).

SINGLE TANK CONS

  • Less back-up in cloudy weather (can be compensated with a larger solar tank which will have a larger back-up capacity).
  • Less solar storage when the element is on (can be compensated for with a larger solar tank which will have more solar storage).

TWO TANK PROS

  • Usually greater back-up capacity

TWO TANK CONS

  • Greater heat loss
  • Larger footprint

The secondary backup tank can’t sense the primary solar tank temperature unless a faucet is turned on, sending the water through the two-tank system.  This causes the second tank to turn on from stand-by losses when the primary solar tank is already plenty hot.

Going all solar requires operating valves as well as turning off back-up.

Personally I’m a fan of single tank systems. For the most part their two main drawbacks can be compensated for by installing a larger tank. An upgrade from a 80 to a 120 gallon solar tank is only a few hundred dollars. For a 50% increase in solar storage it is a small price to pay.

Commercial Solar Energy, Residential Solar Panels ,Solar Service
Written by Lisa Walsh

Going Solar? Top 10 Things to Consider…

SES gives the skinny on going sunny

  1. Commercial Solar Energy ,Residential Solar ,Panels Solar Service1. Cut your Energy Losses
    In most homes, heating and cooling accounts for the most energy usage. Regardless of where your energy is coming from; gas, coal, solar, electric, wind, etc. a homeowner’s first consideration is to reduce the loss of incoming energy:
    • Replace old windows and doors with Energy Star products. This can reduce energy consumption by 7 – 15%.
    • Seal up any air leaks throughout the house, attic and basement.
    • Insulate! This blocks air loss in the winter and preserves cool air in the summer.
  2. Consider those Big Appliances
    Refrigerator:
    Keep the condenser coils clean. Keep refrigerator away from oven/washer/dryer and other heat producing appliances. Place with consideration to air circulation.
    Stove: Remember that gas is generally a more cost-effective choice than electric.
    Attic Fan: An excellent way of pushing hot air outside in the day, and drawing cool air at night.
  3. Need a new roof?
    If you think your roof may need repairing or replacing within the next 5 or so years –it may be worth replacing before the solar panels are installed. If you’re on the fence about replacing your roof prematurely, remember that installers such as SES do provide a Remove and Reinstall service where, for a reasonable fee, the panels will be safely removed then re-installed after re-roofing.
  4. Small Bite or Full Monty?
    Just about every solar energy company sells and installs Solar Electric (Photovoltaic) systems. However, solar water heaters are an entirely different type of solar panel and not every solar company installs them. Thus, not every solar company is likely to tout the cost-effectiveness of this mature technology. Solar water heaters require only a fraction of the roof space (and often a third of the cost) that a solar PV system requires. For a family of four, currently using electric to heat their home’s water – solar water heating may provide the biggest bang for your solar buck, providing around 75% of a home’s annual hot water. However, a family of two heating their water with gas may consider investing in a solar electric (PV) system sized for their usage. Insofar as solar electric (PV), many homeowners cover 60 – 100% of their electrical needs from solar. Some choose to offset as little as 25% and opt to add panels as their budget allows.
  5. READ your Energy Bill
    For electricity, your energy bill should tell you how many kilowatt hours you use per year. This is an important number as you generally do not want to install a system that will exceed your annual consumption. Experienced installers can help you assess this, but a good rule of thumb is to divide that number by 1200kwH and that will tell you the approximate max sized PV system you should consider. That will be represented in kW – probably something like 8 to 10 kW if you are an average consumer. If you heat your water with electric, then solar water heating should absolutely be considered first.
  6. Best way to pay for your solar system
    The beauty of an increased popularity in solar is that there are a number of ways a homeowner can finance their project. Without question, whether immediately or over time, Solar Power is far cheaper than your Utility bill.

Payment plans range from No-Money-Down leasing options to initial investments ranging from $2000 – $50,000 depending on your energy usage and type of solar system. Thanks to current financial incentives, many Marylanders receive over 50% of their upfront investment back the first year. Some of our customers have transferred funds from low yield CDs and even borrowed from 401ks in order to fund their higher-return solar investment. Other homeowners have no interest in ROI’s and fund-juggling and simply want a lowered electric bill/carbon footprint. Thankfully there is a wide variety of financing options available.

  • Know YOUR solar energy tax credits, grants and incentives
    Any solar salesperson worth his/her salt will visit your home with full knowledge of the available financial incentives for your state and county. For example, an Anne Arundel County resident has the good fortune of FOUR different financial incentives (for both PV AND solar water heating) that combine to offer a huge discount on their system. Acclimating yourself to current incentives for your county will help the sales process be much more informative for you. Every solar homeowner is eligible for a 30% Federal Tax Credit. Then SRECs (solar renewable energy credits), state grants, county tax credits differ across the region.
  • Solar Panel Placement
    Whether solar water heating or solar electric (PV), a south facing shade-free roof provides optimum conditions for solar panel placement. However, any shade-free roof – including East and West orientations provide excellent rooftops for solar panels. The number of panels installed depends upon system size, roof space and budget. Homeowners with a good amount of spare land may also consider ground-mounted systems, some of which offer solar tracking options where panels are mounted to motorized pole that literally follow the sun, improving solar efficiency by 40 – 45%.
  • How many solar panels on the roof?
    Insofar as solar water heating, a shade-free area of 64 square feet is typical to house two 4′ x 8′ solar thermal panels (sized to provide a family of four with around 75% of their annual hot water load). Most solar electric (PV) panels measure 3′ 6″ x 5′ 6″. So, a roof that is 30′ wide by 14′ from gutter to ridge will fit two rows of 9 panels. An experienced solar designer will get precise roof measurements and ensure the panels are placed in the most space-efficient and visually appealing design.
  • Choosing a solar energy installer
    Of course, the author of this blog would like to gleefully exclaim, “Choose Solar Energy Services!”. However, most educated consumers know that the best way of finding the best fit for an installer comes from shopping around for the popular 3 proposals/estimates. There are a lot of solar installers our there in today’s market. Some considerations:

 

Time in the Business: This matters. Obviously the more systems a licensed installer has installed – the more experience they’ve gained – and the more they’ve refined their installation technique. Just as important, however, is the question of whether the installer will be around in 5, 10 or 15 yrs when perhaps the incentives for solar have declined. An older company is likely to have deeper roots in the industry regardless of current solar trends and incentives. You want your installer to be around for the life of your system, 25 – 35 yrs plus. This narrows the field considerably.

Service Department: Solar Water Heaters require a 3 – 5 yr simple service visit. Does the installer provide this service?

All Options on the Table: A company who offers both leasing AND upfront purchase will likely lay ALL your options out on the table. This also goes for installers who offer both solar water heating AND solar electric.

There should not be a charge associated with a site evaluation of your home for solar energy. This is a necessary part of the sales process and should take place before the cost estimate/proposal is presented.

Happy Solar Shopping!

solar water heating, solar energy, residential solar panel
Written by Lisa Walsh

Question of the Week: Why Does My Solar Water Heater Run At Night?

solar water heating, solar energy, residential solar panel“If my collector is at 136 degrees, my TST (bottom of tank temperature) is at 161 degrees and my S3 (top of the tank temperature) is at 154 degrees – why is my circulator pump still running? Won’t this cool the bottom of the tank?”

SES says: The pump runs intermittently for a minute periodically when the collectors reach 240 degrees. This keeps the collectors from overheating. Your maximum tank temperature is set to 160. If the bottom sensor, the TST reading, exceeds 160 degrees, the controller will run the pump briefly in the evening to bring the tank temperature back down to 160.

It has been our experience that setting the max temp higher than 160 leads to overheating problems. Yes, you are losing a little heat from the tank when the cooling feature comes on, but at this time of year it is excess heat. You are producing much more hot water than you are using at this time. This is the summer solstice; the collector and tank temperatures will moderate in a few months. Some customers add an extra loop to their solar tank and use that excess heat to heat a swimming pool or hot tub. Most just use control features to manage the excess heat.

Don’t worry about the power consumption. The Grundfos Alpha pump only uses about 5 Watts whether heating or cooling the tank.

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

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.

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