Answer: The size of the system depends on a few factors. The key factor is your yearly kilowatt hour usage. You can get that figure from adding up all your kWh use per month if you happen to save your bills, or you can get it from the internet. Just Google your utility company, bring up your utility company and put in your account number. They will give you a two year history of kWh usage. Your yearly kWh figure can then be divided by a magic number to ultimately arrive at the number of kilowatts of photovoltaic power you will need to power your whole load. The other two factors are your geographic location (i.e. San Diego, California is a bit more sunny than say, Binghamton, NY), and the size of your roof or a sunny area near the house to put your panels. The magic number has to do with the number of full sun hours per year in your geographic location times the average efficiency of the entire system.
Can I run my whole house with solar panels?
Answer: Yes. Average households use between 5,000 and 10,000 kilowatt hours per year. A 5,000 watt system will cover an area of approximately 450 square feet (15 X 30). A 10,000 watt system will cover twice that. A 5,000 watt system in Binghamton, NY will produce 5,601 kWh of energy per year. This is enough to run an average household and will fit on a average roof.
Can I get a really big system to sell back more energy to the utility company?
Answer: No. Most utility companies will only allow you a maximum amount of photovoltaics that they will "net meter" or pay you for the excess energy you produce above and beyond your own usage. Also, in New York State in order to receive incentives to install your system you cannot exceed 110% of your historical kWh usage.
What about snow?
Answer: The panels won't produce when they are covered in snow. The good news is that they are extremely slippery and the snow slides off very easily. If there is a small corner of the panel exposed, it will create heat and a film of water will develop under the snow facilitating the snow removal.
How do I get started?
Answer: You can start by simply filling out this questionnaire to see if you are eligible to become energy independent with solar power.
How long will it take to have a system up and running?
Answer: Generally it takes 14 to 16 weeks from the signature on the contract to flipping the on switch. The actual installation may take anywhere from three to five days. The long lead times center around paperwork and inspections.
Is there enough sun in the Northeast to make a system worth it?
Answer: Binghamton gets 73% of the sun that San Diego, California gets. There is plenty of sun to go around.
Can I heat with photovoltaic panels if I heat with electricity?
Answer: Not the best application. Converting electricity to heating is an expensive way to use electricity. Try a ground source heat pump!