Residential Solar System
Answers to Questions

The awareness to what a Residential Solar System can do is growing fasr and so is the number of people installing home solar systemst. Below, I will address frequently asked questions (FAQ) on solar systems relevant to the typical family home.

• What are the ways to harness sun radiation for residential use?
• Sun radiation can be converted to heat water or air. The second alternative is to convert sun radiation directly to solar photovoltaic electrical power
• Can solar systems work during night time
• No, solar systems derive their energy from the sun. However, solar hot water tanks store hot water for night use and residential photovoltaic can store electricity by adding deep cycle storage batteries. (see bellow links for references)
• What can be done to extend the usability of solar systems overnight?
• Solar thermal systems use solar storage tanks to store enough hot water that can be used over night. Photovoltaic systems use storage batteries or rely on the utility power overnight.
• What are offgrid solar systems?
• off-grid solar systems are photovoltaic systems not connected to the grid and not supported by a utility. They are autonomous and are sized to supply the household electricity consumption day and night
• What is required for installing a residential solar system
• Enough roof area or not-shaded garden area facing south (or south east or south west); typical required size is 5-12 square meter
• What are the required permits?
• Solar thermal systems and solar photovoltaic systems need to comply with local building codes. An on-grid photovoltaic system must be approved by the utility. It is recommended to get an authorized electrician to check an off grid solar system before it is first activated
• What is net metering
• In many states, the utility is obliged to buy back surplus electricity from the grid connected residential solar power system. A bi-directional monitoring (metering) is installed to meter the electricity that the house received from the grid and the amount it supplied to the grid
• What about harsh conditions?
• Most systems are sturdy enough to survive strong winds, hail and snow storms
• What is the life expectancy of residential solar systems?
• Photovoltaic system can live 20 to 25 years is normal, batteries can last 5 to 10 years. Solar thermal systems life expectancy is around 10 years
• Installation Alternatives
• The 2 alternatives are to buy a kit and install it yourself (DIY) or sign a turn key contract with a certified solar contractor
• Do I need backup batteries for power outages?
• It is not recommended in developed countries. Outages are rare and don’t justify the cost and efforts. In countries with outages record, adding batteries need to be evaluated on a case by case basis. It is not recommended to keep the batteries under the same roof with people, there is are risks in doing so. (batteries exhume toxic gases and may explode under harsh temperature conditions)