Types of solar installations
There are a variety of ways to harness the power of the sun. Today we are going to define the ways and discuss them:
- Grid Tied
- Off Grid
- PV Direct
- Solar Thermal
Grid tied systems are solar installations that are implemented on a property that uses utility energy from the grid. These systems reduce the amount of energy purchased from the utility company and the amount of energy not purchased is used to offset the cost of the installation. These systems must have safety switches that cut the connection off when the grid goes down so that you are not feeding solar energy onto the grid while linesmen are trying to make repairs.
Off Grid systems are solar installations that generate and store electricity in batteries for use when the power needed is greater than the power being produced, such as at night or on cloudy days. These systems are not tied to the grid and do not have safety cutoffs. Many people install off grid systems to provide power only during power outages, and only to power certain appliance such as refrigerators to avoid spoilage. Others have full off grid systems on hunting cabins or remote properties where there is no access to utility power. Many times off grid systems will include a Generator to keep batteries charged up during period of prolonged low generation or high usage.
Hybrid systems are grid tied systems with battery backup. They add a layer of complexity because not only do you need to keep your system disconnected from the grid when utility goes down, but you need to switch over to battery power, and for most people drastically reduce your energy consumption. The typical battery bank cannot support the typical household usage for very long. These systems sometimes add yet another layer with a whole house generator.
PV Direct is the most simple way to implement a solar electric system. This system utilizes a PV panel wired directly to a load such as a solar powered water pump. This is a great way to utilize water as a battery, as in pumping water to a higher elevation and then letting gravity distribute it. Another option would be to use a solar panel wired to a fan that circulates hot air out of your attic to assist with colling your home, or even blowing air on yourself.
Solar thermal is probably the second most efficient way to utilize the power of the sun and it is quite simply to use the radiant heat from the sun to reduce energy needs for heating. This could be heating water using a solar water heater, heating air, or heating a thermal mass such as when passive solar is used to heat a house or greenhouse by storing heat and releasing it over time when the temp drops.
Photosynthesis is the most efficient way to utilize the power of the sun as we combine that power with nutrients in the air and soil to allow plants to produce food, shade, and building materials for us. We would be remiss to create a solar site without acknowledging the power of photosynthesis and developing ways to leverage it to our own benefit.