05-30-2007, 02:06 PM
Quote:Still eppie. 1kW/m2 at 100% efficiency in full equatorial sunlight. How many m2 of area would you need for what you consume? What will it cost? What is your monthly energy bill? For my household of 4 it is $200 and we have a fully electric house.
Let's say you are like the average Italian who uses 6000 kWh/year. Pick an efficiency number... For fun lets choose the theoretical achievable 40% (the inverse = 2.5). Assume Italy is like LA (which I doubt since it seems to be rainy at times) and gets about 1860 hours of sun per year. 6000/1860*2.5 = 8 kW avg need. So double it for peak need, and choose a storage mechanism like a huge bank of lead acid batteries. So you, and each Italian around you will need to buy and maintain solar panels between 8 to 16 m2, and the ability to store the excess for night time, winter time, and rainy times. Just the generation portion of the systems here in the USA cost about $9 per watt installed. Your average Italian will need to come up with $70,000 for the initial system, then invest more time and money each year for operation and maintenance. Now, will this system last 10 years ($600+M&O/month)? 20 years ($300+M&O/month)? And what was the energy consumed in making your system?
Again, we will have to alter our lifestyle for sure......we can't continue using the same amount of energy as we do now.....so we don"t need to produce as much as we do now (with we I mean an average european of american because the world energy need will increase).
The solar cells I am talking about will cost around 5 times less, and are using a very small amount of raw material. Despite being less efficient they harvest light in a longer period of the day (harvesting is very efficient, charge transport a bit less) the calculation will be quite different anyway. Once these things have a lifetime of 20 years they will be a very good alternative for the energy we will need.
Especially because in 20 years your electricity bill will probably be also 5 times as high as it is now.