Creating electricity from the sun has been around since 1954, but using the sun for heat energy has been around since the dawn of time. Have you ever leaned against a rock late in the evening that had been ‘cooking’ in the sun all day and discovered it to be warm? That’s solar thermal energy being stored in the rock or ‘thermal mass’. The ancient architects were all over that one!
Despite it’s long history “solar energy” is still a mystery to many.
- Are there different types of solar energy?
- What is insolation?
- How viable is solar in the Pacific Northwest.
There are two general “types” of solar energy – photovoltaic (PV) and thermal. Photovoltaic energy is the suns energy converted directly to electricity. These are the panels you often see mounted to rooftops in sunny climates or the tiny panels built into small appliances and devices such as flashlights or calculators. Of course, the technology and cost has come so far in the past few decades that now many states have utility-sized PV systems feeding into the main power grid!
In contrast, thermal solar energy is a passive. “Thermal” simply means “heat”. This is the warm rock thing I mentioned above. Folks often use this type of solar to heat their pool water or the domestic water used in the house. However, there are some really nifty new technologies opening up in the solar thermal arena, I’ll save those for another post.
Here’s a new word for some of you: “Insolation” (not “insulation”). Insolation is basically how much of the suns energy hits the earth at a given spot at a given time, like where you live. Here in the PNW, sometime around January, we all are looking for more insolation. Knowing insolation levels is critical in determining what kinds of solar systems will work best for a given location.
So… Is solar a viable option in the Pacific Northwest, you ask? Absolutely!
Depending on where you live in the region, you may get up to 4.5 kWh/m2 per day. From solar water heaters to photovoltaics, even in the cloudy Pacific Northwest you can enjoy the benefits of solar energy. As efficiencies in solar technologies increase, the energy output increases, making it that much more appropriate in sun-deprived western Washington!
Make sure you check out the Olympia Solar Tour on October 3rd to see how folks are using it here in Olympia..
Posted on September 19, 2009