The Cost of Solar Energy: how much do you really need?This page is dedicated to informing you about the cost of solar energy and how best to maximize your home needs. Simply by looking at the power consumption of your major household items and your power bill, you will be in a position to make informed decisions about how best to power your home with Solar energy! This will require a little bit of homework, as does anything that's really worth the effort. I wish I could wave a magic wand and tell you what system best suits your needs... but that's not the case since we all have different needs. It's time to get a pencil and paper and your power bill and get to work!
We am currently purchasing our electricity from Origin Energy under the GreenEarth electricity option. The bill our home receives from them tells me several interesting things apart from the overall cost, which include average cost per day, the amount in tonnes of Greenhouse Gases saved, and the average daily use in kWh. It is this last figure that is of interest for calculating my Solar Power requirements.My last four power bills, which cover one whole year, have shown this as the average daily consumption: However, I want to power my home TOTALLY with solar power at all times so I will take the HIGHEST value out of the four, which is 7.9kWh per day. Now I'll have to make an assumption, that there will be an average of 10 hours of daylight each day. I therefore need to generate that 7.9kWh of electricity within those 10 hours. You will need to adjust this as appropriate for your own situation. Here are the steps I used to calculate what size system will meet our home's needs: 1) I need to generate 7.9kWh in 10 hours. That means I need 7.9kWh divided by 10 hours = 0.79kW per hour. 2) Turn that into Watts per hour: multiply by 1000. 0.79 x 1000 = 790 W per hour. 3) Allow some extra for energy losses in the system, cloudy days, decrease in panel function, and so on; to be on the safe side I will add 30% to that figure. I do that as follows: 790 W x 1.3 = 1027 W. Now...DOUBLE IT! Yes, to be able to generate ALL that electricity with current technology solar panels, you'll need DOUBLE the calculated wattage. This is to do with movement of the sun throughout the day, winter and summer differences, and a whole raft of other factors. NOTE: doing this will ensure that the system you install will meet your energy needs continuously, not just most of the time. So it looks like a 2000W system will be satisfactory for our home. BALANCING YOUR HOME'S NEEDS WITH THE AVAILABLE REBATE. Clearly I want to get the best value for money when it comes to installing a rebate-backed solar system into my home. The best thing to do is to investigate the available rebates in your area and match your home's needs to what's available. The Australian Government offers significant rebates to reduce the cost of solar energy home installations up to and including 1000W, so I'll get rebated for that much then I'll have to pay for the rest. Return from the Cost of Solar Energy to Home electricity OR return to the Green Planet home page for more Solar Power Facts.
|
