What doesn't move, however, is a suspended mass inside the seismograph, called the seismometer. During an earthquake, the seismometer remains still while the case around it moves with the ground shaking. Traditionally, the suspended mass was a pendulum, but most modern seismometers work electromagnetically.
Solar electricity costs about $10 to $12 a watt installed, though you may be eligible for state incentives. Check your utility bill to see your monthly usage. A robust solar electric system will cost about $20,000. You can spend as much money, to receive as much solar electricity, as you feel comfortable with.
The average solar energy system size in the U.S is approximately 5 kilowatts (kW). Based on the average price of $3.36/watt, a 5kW system would cost $11,760 after tax credits. Below are some average 2015 quotes for other solar energy systems by size: 6kW solar energy system cost: $15,000. 8kW solar energy system cost: $20,000.