Natural energy from the earth looks very costly compared to traditional types of heating, but there are not enough facts to support this argument. A typical natural gas furnace with central air-conditioning costs about the same as the heat pump, although gas lines and chimney costs should be accounted for. The main installation cost difference comes from the loop in the group, well water transfer unit, excavation and drilling.
The most obvious response to renewable home-heating fuels is firewood, but many developing nations do not have a good supply of wood. Biodiesel is an alternative renewable clean home fuel for heating and transport.
Wood burning is not simply putting a log in your fireplace or using a refurbished wood stove to heat your home. Only stoves that employ advanced technology can burn wood cleanly, efficiently and over long periods. The types of wood-burning stoves that are high-tech are:
Grounding is used to dissipate electrical energy safely when faults occur. This is the third pin on your extension cord plug which allows electricity to flow when system insulation fails.
Drainback installations use three tanks to heat the domestic water supply. The two main tanks are just like those used in pressurized solar thermal systems. However, the third is specialised – the drainback tank, which is installed on the solar loop.
The two main tanks are installed in standard fashion: the one heated by solar energy is piped in series before the backup grid-tied tank, so that the sun-heated supply is topped up with heat in the second tank if necessary.
Unlike pressurized installations, drainback solar hot water systems have a fair amount of head to overcome before they start operating properly. Consequently, they need more powerful pumps. The choice of pump is absolutely critical to the system.
As soon as you start looking into a solar thermal installation, you will run into certain terms and principles that may be unfamiliar. It is essential that you understand these ideas, so that you can see what is needed and make intelligent decisions when offered choices by professional installers.
One of the advantages of a pressurized solar hot water system is that the solar loop is always full. This means that the pump has no static head pressure to overcome (just friction head), so low-head, slow-starting pumps can be used effectively. And those pumps can be run on power from a PV array, eliminating your grid-tied power costs for operation.
Drainback solar hot water systems are not as flexible as pressurized systems, but still work very well in both residential and business applications. They are very efficient if they are planned and installed carefully.
These systems have many advantages:
It's also important to consider these disadvantages:
