October 2007 Archives
I pointed out this SlashDot article to a friend, and his question was, isn't 1$/watt too expensive?
My response:
$1/watt is not like your electricity meter. It's the cost of the panel that can produce one watt.
For example:
Amazon Solar Panel for 80$
So, a 15 watt panel costs 80 bucks. that'd be 5.33 bucks per watt.
For example, my monthly usage is 1000 kwh. Assuming I use electricity uniformly, that would mean, for 30 days (720 hours), I use 1000kw. So, my load will be 1000,000/720 = 1388watt on average per hour. Round it off to 1.5kw
So, If I want to use a solar panel, I'd need a 4.5 kw panel (assuming I get full sunlight only for 8 hours a day). That'd cost me 24k for just the panel.
I paid 200$ for electricity in the 1000kwh month. So, to recover my cost, it'd take me 10 years (just for the solar panel, I'm not talking about battery and other equipments here). My solar panel will be near end-of-life in that many years. Plus, solar panels never give full wattage. That's just the best case scenario.
Now, if I have a 1$/watt panel, I get it back in (4500/200)=22.5 months. Now that'd make a lot of sense. Even if I get it back in, say, 5 years, and the solar panels are made to last, say, 15 years, you'd save about 24k. Nice!!
My response:
$1/watt is not like your electricity meter. It's the cost of the panel that can produce one watt.
For example:
Amazon Solar Panel for 80$
So, a 15 watt panel costs 80 bucks. that'd be 5.33 bucks per watt.
For example, my monthly usage is 1000 kwh. Assuming I use electricity uniformly, that would mean, for 30 days (720 hours), I use 1000kw. So, my load will be 1000,000/720 = 1388watt on average per hour. Round it off to 1.5kw
So, If I want to use a solar panel, I'd need a 4.5 kw panel (assuming I get full sunlight only for 8 hours a day). That'd cost me 24k for just the panel.
I paid 200$ for electricity in the 1000kwh month. So, to recover my cost, it'd take me 10 years (just for the solar panel, I'm not talking about battery and other equipments here). My solar panel will be near end-of-life in that many years. Plus, solar panels never give full wattage. That's just the best case scenario.
Now, if I have a 1$/watt panel, I get it back in (4500/200)=22.5 months. Now that'd make a lot of sense. Even if I get it back in, say, 5 years, and the solar panels are made to last, say, 15 years, you'd save about 24k. Nice!!
