Battery System for My Home


We speak solar and energy efficiency all day. We thought you might benefit from learning a few of our key terms that you might find helpful in deciding if solar is right for you.  Blue Sky Energy is pretty passionate about energy efficiency and we want to share our knowledge with you.


A method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect.

Investment Tax Credits

The federal energy investment tax credit (ITC) program, authorized under 26 USC 48 (section 48), encourages the use of renewable energy, including solar energy property that generates electricity, illumination, or solar process heat. The energy ITC program reduces federal income taxes by offering a tax credit equivalent to 30 percent of the total cost of installation to owners or long-term lessees for qualified property that meets established performance and quality standards. Currently this program runs through 2016.

Solar Thermal

A solar thermal system uses specially designed solar panels that absorb energy from the sun. This energy is then used to power things like hot water heating systems, under-floor heating, and swimming pools. Solar thermal panels are usually made up of tubes, known as collectors, filled with a fluid similar to antifreeze, that warms up when exposed to the sun. The warmed-up fluid is then pumped to a cylinder containing heated water. The cylinder is usually connected to a normal electric immersion heater that can top up the temperature of the water if it is not high enough. This is primarily utilized for heating domestic hot water and pools.


Leadership in Energy and Environmental Design is a voluntary, consensus-based, market-driven program that provides third-party verification of green buildings.

Tiered Rate Pricing

Most utilities use tiered pricing for residential and commercial customers, at least for a portion of the year. Under tiered pricing structures, customers are charged a low rate for a specified amount of usage, and then higher per-kilowatt amounts for usage beyond this baseline. The more you use, the more you pay. Such rate structures are designed specifically to encourage on-site electricity production and conservation.

Time-of-Use (TOU) Pricing

Utilities predominantly use time-of-use pricing for commercial customers, but such rate structures are slowly making their way into the residential sector. As one might assume, under time-of-use rates the customer pays varying amounts for electricity depending on the time of day the electricity is consumed. Generally, prices are higher when electricity demand is high, such as summer afternoons, and lower in the evening and in cooler months. Time-of-use pricing typically requires a “smart meter,” and generally provides even more encouragement for solar and energy efficiency measures than tiered-rate pricing.

Solar Irradiation

The total amount of solar energy accumulated on an area over time.


1 kilowatt = 1,000 watts; can be measured in both DC and AC.


A kilowatt hour (kWh) is the way that we measure our electricity usage and get charged for it (or paid for it, if you are creating your own energy and feeding it back into the national grid). One kilowatt is equal to one thousand watts. A kilowatt hour therefore is reference to an appliance or device using one thousand watts of electrical power per hour. A simple example would be to think of burning a 100 watt light bulb for an hour, this would use 1 kWh of energy.

Cool Roof

The most well-known type of reflective surface is the cool roof. While it is true that cool roofs are mostly associated with white roofs, they come in a variety of colors and materials and are available for both commercial and residential buildings. Note that today’s “cool roof” pigments allow metal roofing products to be EnergyStar rated in dark colors, even black. They aren’t as reflective as whites or light colors, but can still save energy over other paints.