Grid-tied solar energy systems.
Most solar electricity systems are designed to operate alongside the electricity supplied by the local power company. Here’s how it works:
1. During sunny days, your grid-tied system will generate some (or all) of the electricity you need, resulting in a lower monthly bill from the power company.
2. If your solar panels are providing more electricity than you’re using, the system will feed the surplus power back to your utility company. This results in a billing credit.
3. At night, all your electricity will be supplied by the power company.
The size of the system you are planning to install will determine how much of your electric bill will be replaced by solar power.
Residential Solar Energy Systems
Very few homes have adequate roof space to install a system large enough to offset all of their electrical usage. However, the portion of your consumption that the system does offset, comes at a very attractive savings. Residential systems typically range from 2000 to 10,000 watts (2kW-10kW)—around 20-80% for most residential homes.
Commercial Solar Energy Systems
Commercial systems are often much larger. They typically range from as little as 5000 to 100,000 watts (5kW-100kW) or more.
Roof Mounted Solar Energy Systems
In Oregon, a south facing roof is exposed to the most year-round sunlight. A solar electric system needs to be installed on a roof which is oriented as close to south-facing as possible, with minimal shading from trees or other structures. The first step in determining whether your property is a good candidate for solar energy is to measure the square footage of your south-facing roof area.
Ground Mounted Solar Energy Systems
If your property does not have an optimal roof surface, ground mounting is the next best option. Ground mounting is more expensive than roof mounting, but it does provide two important benefits: ease of cleaning and reduced cost when re-roofing is required.
Should I install a battery back-up?
Most solar electric systems do not have batteries. For customers residing within one mile of the grid, it is usually more cost-effective to augment power from the grid with your solar electric system.
When the sun isn’t shining, a solar electric system stops producing power. The only way to receive power from your solar panels during the night or on a cloudy day is to install a battery back-up system. While this makes sense in certain situations, it isn’t appropriate for everyone. Batteries add substantially to the initial cost of the system, they must be replaced periodically, and many require regular maintenance. In fact, when you factor in the replacement cost of a battery bank, the savings in your monthly utility bill may not off-set the cost of battery back-up. And when you also consider the fact that a battery system can only power a small load for a short period, you can see why most customers choose to forgo batteries.
If back-up power is essential to your system, we recommend a gas powered generator. More cost-effective to purchase and install, a generator can power larger loads for a longer period of time. Generators also have a lower life-cycle cost than batteries, and the occasional use has minimal environmental impact.