Installing wind and solar, the how, the why, and what will it cost me?
So today I find myself putting together the costs required to transform my grid-tied home to solar or wind power, and trying to calculate how much power I might need on my home and my workshop to self produce power. I'm here looking at my electric bill, and trying to figure out how many solar panels and wind turbines it might take, and what that cost would be. I used 46,578 KWH of power this past year, with the average monthly usage of 3882 kwh. One kwh (or kilowatt hour) is 1000 watts of power used for one hour.
Here is a good video that will help the understanding it takes to make decisions about the installation:
So if I am able to buy decent solar panels for about $1.00 per watt plus tax and shipping, and say that works out to about $1.20 per watt total, how many watts do I need? Well for the average month of 3882kwh for the month, divide that by 30 days, and divide that by 24 hours in a day, and that works out to 5.391 kwh on average. That means my home is running 5,391 watts of power every hour all day and night on average. So on the lighter side of things, in order to produce that much power, consider that solar panels produce about half their wattage or less, because they are not producing at night. So panels that are rated for 300w can't be counted for 24 hours per day. Depending on how direct their sunlight, and how many hours of sunlight, that effects how much power they produce. So If I have 20 of them, that would produce 6000w of power in direct sunlight. We're getting closer. But to be safe, if I wanted to produce enough power for my home, I also need to account for the fact that peak hours might use 10,000 watts of power. For solar power, I think I could use up every bit of the power produced by 40 solar panels. In peak sunlight, that would be about 12kw of power production, but then nothing throughout the night. Through net metering, I should be able to offset the low producing times with the overproducing times. So just for the solar panels (not counting power inverters, charge controllers, mounting hardware, or any other gear), I'm looking at $14,400 in panels.
A comparable wind turbine that would produce power 24/7 in windy conditions would be a Kohilo Vortex V5, which produces 8980 watts of power with a windspeed of 26.8 miles per hour, and cost about $14,900 (not including inverters, mounting hardware, or labor. If the windspeed ran year round, the output would be far greater than the 40 solar panels. If it was less, then it may run less power output than the solar panels. But the mounting hardware is much simpler and cheaper for the single wind turbine than for the multiple solar panels that would weigh down an entire roof. So you can see that figuring out your benefit based on continuous wind speed vs sunlight in your region is important.
Regardless, a solution of all wind or all solar could leave you wanting in lighter producing periods. I recommend a combination of both.
I'm a big fan of the new Kohilo wind turbines, because they have magnetic bearings with no resistance, and because they are much smaller, and direct turbulent air into the vortex producing more power for the space required at lower elevations (means you can install it on a shorter pole), and with less noise than other wind turbines. Also, they are light, and less cost than many comparable turbines.
Depending on your setup, as you can see, for a house this size, the cost of adding wind and solar power including installation, delivery, mounting hardware, and inverters, for a grid-tie system, could easily go beyond $60,000.00. Considering an average electric bill is about $250.00, and the cost of financing $60,000 over the course of 20 years at 8% interest would be about $500.00 per month, it doesn't make financial sense to perform this type of installation with the solar power and wind power combined, but consider that that's with a plan to overproduce by double. If I reduce costs by installing only 20 solar panels, and a less powerful wind turbine, say the Kohilo Vortex XL at a cost of $4165, I would spend more like $25,000-$30,000 on the whole setup, and financing would bring my costs down to about $209 per month before any rebates and at a high interest rate of 8%.
Note that there are far fewer costs associated with the wind power option than solar, and it will better cover its costs if there is sufficient wind.
What really makes the difference in todays marketplace is the value of the tax rebates you recover for using green energies, which are varied dependant on your State or country. They can help make it easier on you to switch over. As with any construction project, the more you take on yourself, the less out of pocket expense. So if you build your own mounting system for the solar panels, and install them, you will save yourself a lot of money (and gain yourself a lot of work).
Overall, the best solution is to downsize your homes energy use first, or build a home with much reduced energy usage. Heating and air are the most impactive on power usage. Changing the way you heat or cool your home can have a big impact on costs, and will reduce your utility spending immediately. Then when you provide a source of renewable energy to your home, the up front cost factor will be much reduced.
If you are interested in a solar or wind power installation, email me your contact info (include phone and location)to email@example.com, and I'll put you in touch with someone who can help you with your setup. With any grid tied option, you can always install a bit of power, and add more later.