Is it time to cool our homes with the sun?
According to scientists, every summer that is passing by is getting hotter. Electricity bills are also rising each year as homeowners and businesses have to work their air conditioning units harder to combat the oppressive heat. So, why don’t more people take advantage of the extra sunshine to generate electricity that can be used to power the air conditioning units?
It is time we took a look at the technology available.
Solar panels are usually used to help reduce the cost of heating water. We have discussed solar hot water systems already; however, surely solar power is ideal for running air conditioning – the sunnier it gets, more electricity is produced, so there will be more power for the air con.
We know that it certainly works – the Rappler spoke to a homeowner in the Philippines who installed solar panels and saw his electricity bills drop by 50 percent: the most notable change was with the air conditioning. Mike De Guzman installed 20 solar panels on his roof and these produce 675 kilo-Watt-hours (kWh) per month).
It was when he turned on his air conditioning that he realized how important the panels were: “I put it in this house, I turned it on, I turned on my aircon and the meter wasn’t moving. Then I knew I stumbled upon something,” he told the Rappler.
Philippine electricity rates are one of the highest in the world in relative terms, so being able to reduce bills and effectively get free air conditioning is a huge financial benefit.
In the hottest part of the summer De Guzman’s solar panels can produce up to 34 kWh in one day. This is enough electricity to run his air conditioning for 45 hours. In fact, since installing solar panels he often has more energy than he can use.
“I had so much power I didn’t even know what to do with it. Last summer, I just turned on my aircon and put the dog in the living room because I had a lot of power. I could use 3 aircons and not use a watt from Meralco.” Meralco is The Manila Electric Company.
Meralco has since launched a net metering program that buys back excess electricity. So now, in addition to producing all the electricity he needs and having his air conditioning running 24 hours a day, De Guzman is saving money by selling electricity to The Manila Electric Company. The Philippine net metering program works by allowing homeowners to develop a surplus during the day and then use Meralco power in the evening, but at a price reduced for providing solar power to the system. De Guzman just pays a modest monthly fee for this service.
De Guzman has found that this system is especially beneficial when he goes on vacation: “It comes in handy if you go for vacation for a month or you’re out of the country. Then when you come back, you’re going to have a lot of credits because your panels were generating energy all that time. Eventually you’ll use it all up within the year.”
The big question is, is it really affordable? It certainly is in the Philippines. De Guzman paid around $11,600 for a 5 kW solar panel system and said: “It will pay for itself in 5 years. The solar panels themselves will last for 25 years. It’s better than a time deposit.”
The most promising part of this story is how solar panels help the national grid. In the Philippines the grid is under such demand between 10am and 2pm that Meralco often has to buy power from coal and diesel generators at very high rates. This is the time when solar panels are producing the most energy. If every home and office had them the daily spike in demand would probably cease.
Things may be a little different in America. The cost of installing and buying solar panels may be higher in relative terms and it may be difficult to produce adequate solar energy every day to cover the cost of air conditioning.
However, this idea is not new. In March 2007 CNET ran a story called “Using solar energy to keep homes cool” and Martin LaMonica discussed the SolCool Millennia version 4, a hybrid solar air conditioner. This was an air conditioning unit that was designed to run on a very small amount of electricity. The unit consumes a maximum of 500 watts, about half of an average air conditioning unit.
In 2007 the SolCool system had already been in development for four years. A quick search reveals that the business is online and they are advertising their Millennia 1.5-Ton HVAC Direct Current System. This is a system that provides both aircon and heating so it can be used all year round. It also comes with a 2 to 12 hour backup battery that means it can run after the sun goes down.
Today there are several other products in the market, including Solar Powered Window Air Conditioner and a ductless unit, both made by Kingtec Solar.
So, rather than complain about the hot weather and rising bills, why not install solar powered aircon? Give us a call and we will be happy to advise you.