Solar Photovoltaic vs. Solar Thermal
One of the most asked questions we get is whether a person should get solar photovoltaic panels or solar thermal panels. While the answer to that question lies in how much direct sunlight a roof gets, how big a roof is, and other factors, we thought it’d be helpful to first understand the differences between the two types of solar panel systems.
Solar Photovoltaic
Also called solar electric, photovoltaics are primarily used to provide energy to your home. They consist of an array of photovoltaic cells, made of silicon, that capture sunlight and convert it into energy. These systems integrate with your electric company’s power grid, off-setting the amount of energy you receive from the power company. Solar electric systems allow you to receive the financial benefits of both SRECs and Net Metering.
Solar Thermal
Solar Thermal systems, also called solar water heating systems, collect the sun’s energy and use it to heat the water in your house. The panels contain tubes filled with glycol, a non-toxic liquid similar to anti-freeze. Solar thermal panels trap the sun’s heat, which heats the glycol. Then, the glycol is moved through the tubes to a heat transfer system that heats your water. Depending on the size of the system, you can heat the water you use for bathing and washing. Or, if your home is heated with water radiant heat and can support a larger system, you could heat your entire house! Either way, you’ll save a lot of money on your electricity bill.
How to choose the right system
There are many factors that go into choosing which type of solar panel system to install. Here are a few questions that we typically ask when we do a solar analysis:
- Do you want to reduce or eliminate your electric bill?
- Are you concerned about future energy costs?
- Do you want to have a positive impact on the environment?
- Are you concerned about the appearance of a solar panel system?
- How much space do you have?
- Do you want to improve the resale value of your home?
- How much are you currently paying for electricity?
Green Living: Recycling Electronics
In last month’s Green Living, we talked about recycling. This month, we’d like to focus specifically on recycling electronics, sometimes called “eClycling.”
In our gadget-filled world, people are buying more electronics than ever before, including cell phones, computers, laptops, TVs, DVD players—you name it. According to the US Environmental Protection Agency, in 2005, discarded electronics totaled about 2 million tons. Only about 15 – 20 percent of it was recycled. These products, while certainly great to have and use, they contain toxic chemicals such as mercury and lead that can pollute the environment and cause contamination and serious health problems.
Fortunately, Maryland and DC offer eCycling programs that accept household electronics for recycling. These programs ensure that electronics are properly disposed off, rather than contaminating our environment.
You can read more about Maryland’s eCycling program at the Maryland Department of the Environment.
You can read more about DC’s eCycling program at the Department of Public Works.
Additionally, if you want your used electronics to go to a worthy cause, you may want to consider donating them. Often times, schools and nonprofits will accept these types of donations, so check with your favorite nonprofit to see if you can donate your old, unused electronics.
Back to Basics: Solar Renewable Energy Credits (SREC)
There are many factors that have made solar panels for your home more affordable in recent years, but Solar Renewable Energy Credits, or SRECs, are possibly one of the most important.
So what are they? Think of them like a stock. One SREC represents the monetary value of 1,000 kilowatt-hours (kWh) produced. That value changes every day based on how much energy is produced across the state, how much energy is being used, and what portion of that energy comes from renewable resources (which includes wind power generation, geothermal, biomass, etc.).
In an effort to combat the effects of climate change and dependency on foreign oil, federal, state and local governments require utilities to have a certain percentage of their energy produced from renewable resources. In Maryland, utilities are required to have 15% of all electricity generated to come from renewable energy sources by 2022, of which 2% must come from solar power. Those percentages are phased in over time, which means that each year utilities must either produce that energy themselves or purchase energy credits.
And that’s where the value of SRECs is determined. It is easier and less expensive for utilities to purchase credits than to build new energy production facilities. The less energy they produce from solar and other renewable, the greater the value of the SRECs. And as energy demand continues to grow, the value of those SRECs will also continue to grow. That means that the longer you keep your SRECs, the more valuable they will be.
How many SRECs your system earns each year will entirely be based on the size of the system. When we do a solar analysis, we help you calculate what the cost/benefit is, taking into account the SRECs your solar panel system will earn.
Take note: a solar thermal system (also known as solar hot water) does not earn SRECs! They can, however, help you dramatically lower your utility bills.
Also note: SRECs are not the same as net metering, which requires utility companies to give solar electricity owners a credit if their system generates more electricity than is supplied by the grid.