Solar energy is an alternative to fossil fuels for providing electrical power for both homes and businesses. It may be locally produced and used at the same location as the panels, which reduces distribution costs and lessens risks in natural disasters. Alternatively, large facilities may be located in available space and the power added to the "grid" that distributes electricity.

In our area of Kentucky, the regional power production is 3.5 gigawatts (GW). It is supplied by Louisville Gas & Electric Company, now a subsidiary of a large conglomerate of power companies supplying energy to Kentucky and Virginia. This energy is derived by burning natural gas and coal for the most part, but it is supplemented with energy from hydropower using dams on the Ohio River, and from asolar farm with sheep that produces about 10 MW.

A gigawatt (GW) is 10⁹ watts. A megawatt (MW) is 10⁶ watts. A kilowatt (kW) is 10³ watts. A watt is 1 J/s. A kilowatt-hour (kWh) is the energy of 1 kW delivered for 1 hour, that is for 3600 seconds.

1. The Sun provides approximately 1.4 kilowatts (kW) of energy adding all the light striking one square meter perpendicular to a line to the Sun above the Earth's atmosphere. If solar panels are 25% efficient in converting this optical energy to electrical energy, and if they are oriented to make maximum use of incident sunlight, how much panel area in square meters is needed to develop all of the regional power production while the Sun shines? Take the square root to find the dimension of a square site with that much area.

2. If you could pump water to a height of 300 meters, say to a reservoir on a mountain above a generating station, how much water by volume would have to be moved to provide 3.5 GW of power for 24 hours? This method of pumped water energy storage is used on a smaller scale for energy production in Tennessee and Massachusetts. (Use the potential energy of gravity, mgh, to figure this out. The density of water is 1 g/cm³, or 1000 kg/m³.)

3. The 2023 Chevy Bolt EV car has a battery with a capacity of 65 kWh that provides an estimated range of 397 km. Its efficiency is about 18.0 kWh/100 km when it is being driven. Given what you know about the physics of solar, comment on the viability of it as a sole source of power for your home and your rechargeable electric car. If you have a clever way of storing energy, mention it here too. Where does the electricity to power these come from now?

4. If your home produced 10 MWh of energy annually from solar panels, at a voltage of 120 V what would be the average current in amperes that the panels provided?

Answer rating: 100% (QA)

1 To find the amount of panel area needed to develop all of the regional power production we first need to find the total power output of the region T... View the full answer