Solar Panels?

I wanted an estimate of how many solar panels I will be needing and how much will they cost, and their lifetim?

• Hi, I wanted an estimate of how many solar panels I will be needing and how much will they cost, to run a whole hospital on them. This hospital has over hundred rooms with at least two tube lights and a fan and a TV in each room. I want to use solar panels without having to use electricity, "ever"! I know solar panels have a Lifetime period, but I can get new ones when these stop working, I also want to know their lifetime period. I need them here in Pakistan, there is plenty of sunlight. I want a rough estimate. Please, can someone help me? Thank you in advance! Also, the hospital has air conditioners all over! I don't want to use normal electricity at all, I'm talking about living on solar energy(alone).

• Answer:

  It is not practical to run the whole hospital on solar alone. This is because the solar system produces no electricity when the sun is down. You would need a massive battery set. Also it is not practical to run the hospital during daylight hours on solar alone. To verify this you could determine the electrical demand at a busy time of day, when air conditioners are running. I expect it will be over 100 kilowatts. At 100 kW per panel, and with 200 watt panels, you would need 500. And that would be if they were 100% efficient. Considering losses due to voltage drop in conductors and losses in inverters, 75% efficiency is what might be expected. And then you must realize that the system generates maximum power only around noon. As the sun rises and sets the output goes from zero to maximum and back to zero again. With that many panels the system would supply sufficient power for only a few minutes each day. If you want to utilize solar for part of your electricity you can look under solar panels to determine how much they would cost. To that you would need to add the cost of inverters and installation. You might consider installing the panels as shade structures on the parking lot. I am sorry to disappoint you.