What is the difference between solar hot water systems and solar energy for electricity?
Solar hot water systems, sometimes called solar thermal systems, use the direct heat from the sun to heat water, whereas solar photovoltaics "pv" uses sunlight to produce electricity. They are two very different types of technology. Both solar technologies use panels to collect the suns energy. Solar hot water panels have black copper pipes running through them filled with water. Solar photovoltaic panels generally have silicon cells. It is not practical to have one panel to do both jobs.
Up until 2005 solar hot water systems were the only readily available solar technology on the market. They realised savings for households but they have a number of shortcomings. In winter they rarely produce enough hot water and need expensive 'boosting' by gas or electricity. Conversely in summer they produce far more hot water than can be used. In the last 10 years solar electricity has taken off and become very affordable. One of the big advantages of solar pv is that free electricity can be used to power hundreds of things in the home or business whereas solar hot water is a one-trick pony in that it only heats water and in most homes hot water use is actually declining due to dish washers, washing machines and shower heads being much more water-wise. In many households it no longer makes financial sense to replace or install conventional solar hot water system because larger bill savings can be realised for a smaller investment by installing a large solar pv system to power both the house and heat hot water via an electric element or heat pump.
PV solar panels (in background of photo) generate a flow of electricity when hit by sunlight . This generated electrical energy, when harnessed and sent through an inverter, is converted into usable electricity for electrical appliances. LG manufactures solar panels (LG's automated solar factory) to generate electricity and does not manufacturer solar hot water systems, like the one in this photo.