Solar for Your Home – Recap & Resources

Below is a summary re-invented in question form of our informational meeting and Q&A on Solar for Residential from November 6, 2013.

What’s PV and Thermal?

PV stands for photovoltaic, referring to Solar Photovoltaic System. Thermal is short for Solar Thermal or Solar Hot Water System.

How does solar work?

PV: DC power is created by the solar panels and via the inverter, converts it to AC power. If the panels produce more power than you need, it goes to the grid; the grid is the “battery”. If the panels don’t produce enough, then you draw energy from the grid.

THERMAL: Ditto, except any energy not used in this system is simply not used. The sun heats a glycol solution in the solar panels that heats the water in a larger-than-average hot water tank through a heat exchanger.  In the summer, the water in your hot water tank will get extremely hot and a safety valve mixes it with cold water to achieve a safe temperature for your tank. It provides 70-90% of your hot water needs. In the winter, when the solar hot water system may not meet all of your needs, a back-up system (such as your boiler or an electrical immersion element) will supply energy for the balance. Solar thermal can also be used to heat your home – think radiant flooring. The economics  favor using solar thermal for hot water, while the economics for radiant flooring depend on the specific situation.

Is solar a viable option in Massachusetts?

PV: Yes. Solar City was quick to point out that we are not Arizona, but we can still benefit. Germany generates 60% of its power from solar and they have less solar gain than Massachusetts. (The U.S. generates less than 1% of its energy from solar power.) Fun activity you can do at home: Compare a map of solar installations across the country with one of states by political party affiliation.

THERMAL: Yes. China has installed solar hot water in 50% of households. I’m just going to say that again because I need to, 50 PERCENT.

Is it going to get cheaper?

PV: According to Solar City, the price of a solar panel has dropped about as low as they can go, nearly matching the cost of production (See also Incentives and SRECs offset the cost of installation, though in 2017 the rebates will drop from 30% to 10% of cost. MA allows state income tax credit of 15% of the installed cost (up to $1000).

THERMAL: The technology for solar thermal has not changed in almost 30 years – it is 60-70% efficient, i.e., hard to improve on that!

What are the reasons for going solar?

PV: 1) Lower energy costs for you, the consumer; 2) Control – you are not subject to energy cost fluctuations because you own (or lease) your energy supply; 3) Good for the environment – it was acknowledged that if this were the only ‘win’ it would rarely be done.

THERMAL: Ditto. Hot water accounts for roughly 30% of energy consumption in an average home, so replacing with a solar system is the rough equivalent of removing 1 average car’s carbon emissions for a year, every year you run the system.

What’s required of a residential site?

PV: Among the considerations are a roof facing any direction other than 45° of  north; in good condition – not needing to be replaced within 5 years; an absence of major trees projecting shadows on your roof; pitch of roof. Fun fact: the array covering your roof can actually extend the life of the roof because sun is a primary source of degradation AND it actually helps to keep your roof cooler in summer.

THERMAL: You need about 8×8 feet of solar panel installation – they can mount it anywhere. (That’s cool.) The same roof quality tests apply.

Should you buy or lease?

PV: Like any other financial decision, it depends on your finances. Solar City will tell you that the majority (267 of 270 this year) chose to lease. If you own: you get the SRECs and the rebates, they cover maintenance and guarantee. If you lease: they cover insurance, maintenance, warranty, remote monitoring and you make payments based on your plan – Solar City gets the SRECs and incentives.

THERMAL: A less expensive investment – buying is the only option, though there are some great low-interest loans and the tax incentives bring the price tag down considerably. Storage tanks are either stainless steel (20 yr) or glass lined (11 yr) – within this lifespan it is important to consider how often one would have to replace an existing hot water heater with multiple replacements yielding additional avoided costs (a.k.a. savings). The payback period largely depends on your current heating source for your hot water, with conversions from oil and electricity yielding the shortest payback periods.

Why don’t we [Belmont residents] get more incentives?

PV: We [Belmont Light, formerly BMLD] do not benefit from the Mass Save programs (pertaining to electric, but can get gas-related incentives), however you can obtain tax credits from the state depending on your purchase or lease options.

THERMAL: We [Belmont Light] do not benefit from the Massachusetts Clean Energy Commission since we do not contribute to it.

What if I move?

PV: A small increase in value, perhaps 5 to 10 K, and tend to sell faster. Solar City oversees the transfer of a given lease to the buying party. You would be crazy to de-install and reinstall, but no one will stop you.

THERMAL: With Solar Hot Water, you reap the benefits quickly on your own financials and these would undoubtedly yield some value increase to your home.

What does the future hold?

PV: Belmont Light is changing their policies around solar buy-backs, anticipated by the 2nd quarter of 2014. The rate at which they will buy back excess energy from your panels will be at 40% of retail, i.e., wholesale price. This is a considerable shift from their $ for $ price now, but not unprecedented in the market. It will impact the big picture of savings for a company to lease you solar panels, but Solar City has a good working relationship with Belmont Light. Also note, systems are installed/designed to meet the needs of the consumer and not exceed them.

THERMAL: Belmont Light’s changing policies do not affect thermal, since the system is not tied to the grid. And, because it’s not tied to the grid and the technology is stable, only the incentives can change.

Tell us about your experience, Darrell?

Darrell has conscientiously worked to reduce his homes total electrical (and not doubt other energy) consumptions, such that his monthly bill was quite low before switching to solar pv. When some down trees on his property made his roof more viable, he took advantage of the leasing option and incentives he was eligible for. His system has been in place for almost 15 months and his credits with Belmont Light are still accruing. He did acknowledge for a few days last winter the panels failed to produce when we had the the most significant snowfalls.

Tell us about your experience, Rebecca?

In need of cost savings and facing a new boiler down the road, Rebecca opted for the Solar Thermal route and has delighted in the economic savings and lower carbon footprint. She felt secure in her decision in that the technology has been enduring of the years and her vendor was up front with the costs, such that she didn’t see that another resident would be getting a very different installation price, though the credits differ. Also having her system over about 2 years, Rebecca installed a gas boiler, so was unable to compare enough data pre-solar and post, but revelled in that she only recently has had to turn on her back up system for the times the solar is unable to deliver.

Thank You!

Our industry representatives accounted for a considerable presence in the national and state markets. Solar City has completed over 50,00 projects and holds 25% of the market share. New England Solar Hot Water has completed over 1/3 of the solar hot water projects in Massachusetts, though this is a much smaller overall market.

We are extremely grateful that Corey and Bruce, who lent their time and expertise to our community and to residents, Darrel and Rebecca for sharing detailed experiences on their decision-making – Thank you!

For anyone interested in solar systems, please you are welcome to consider these vendors as a starting point. Sustainable Belmont does not endorse any particular vendor or system, but we advocate for cleaner energy as it relates to improving and preserving the environment, Belmont in particular.

Belmont Solar Challenge (Exploratory Phase)

For our December meeting, we will be introducing the Belmont Solar Challenge – a community effort to get group discounted pricing on solar PV similar to communities that are served by the Mass CEC. Please join us for that to learn more or volunteer with the effort. More information here.

As promised, the links mentioned during the talk, as follows:

Solar Pricing in Massachusetts. All solar installations that receive rebates from Mass CEC are reported in the following excel spreadsheet. Because Mass CEC receives funding from investor-owned utilities and Belmont has a municipal utility, you will not see Belmont solar installations on this chart. It does, however, provide a good summary of costs in the Greater Boston region and shows the activities of the various installers. 2013 installations start at line 6480.

Economics of Leasing vs. Ownership. The Massachusetts Department of Energy Resources has commissioned a comprehensive economic report on the economic impacts and benefits resulting from different PV ownership and financing structures. They specifically compare homeowner-owned systems financed through a local community bank loan (direct ownership) vs. third-party ownership with a power purchase agreement (leasing panels; also called third-party ownership). Financing through a bank gives homeowners a dramatically better return on their investment (see table 5 on page 9). If financing is not possible given your personal situation, leasing still gives you savings and an important reduction in your carbon footprint.