Being More Comfortable In Your Home
Building a home is an exciting life goal and one of the largest expenses many people ever undertake. The decision-making processes necessary to put together a living space can feel overwhelming. A huge number of options exist for everything from exterior siding to floor covering and light fixtures. Something that commonly doesn't get a lot of attention in this task is the home’s electrical system. Electrical energy enables so many of the aspects of day to day living and is a worthwhile area to consider carefully when approaching homeownership.
When thinking about electricity within a home, some of the decisions include the number of electrical outlets, light fixtures locations and provisions for high voltage electrical appliances. These are all important considerations and should be undertaken with careful thought and consultation with electrical contractors. Other areas involving electricity for the home include selecting the retail electricity provider and possible back-up power provisions. Another option that has begun to gain popularity and availability is that of incorporating solar energy. If solar energy is something a prospective homeowner is interested in, educating themselves about this option is important. It involves more than just finding and buying solar panels and putting them on the roof.
The phenomenon that makes solar energy possible is the photovoltaic effect. Alexander Edmond Becquerel discovered this process in 1839 while experimenting with light and different materials. He observed that, when certain metallic materials were exposed to light, an electrical potential, measured as a voltage, developed between connections to the metals. Eventually, this led to the invention of the solar cell. A solar cell a small electrical circuit that incorporates semiconductor materials that have been specially treated chemically to maximize their photovoltaic properties. These cells vary in size from a few millimeters square for handheld calculators up to several inches square for other applications.
A solar energy system for a residence is constructed with several different components. The number of components needed depends on the amount of energy output desired and choices about whether energy storage will be included. One way of categorizing these systems is to divide them into grid-connected and off-grid designs.
Grid-Connected Solar Energy Systems
The electrical utility industry provides residences with standard alternating current electricity (AC). It is called alternating current or AC because it is delivered as a continuously changing wave of electrical voltage and current. This differs from the electrical energy produced by solar cells which is direct current (DC). DC electricity is the kind of electrical energy stored in batteries. Rather than being a continuously varying waveform, DC electrical energy is delivered at a constant voltage level.
Because of this difference, a component must be added to convert solar system DC energy into AC if the system is to be connected to the utility grid. That converter is called an inverter and consists of electronic circuits that receive the DC energy from solar cells and manipulate it to create the waveform characteristic of the grid electricity. The addition of an inverter also allows the homeowner to use off-the-shelf existing appliances and devices that run on AC power.
Off-Grid Solar Energy Systems
Some homeowners elect to install a system that does not connect to the utility grid. Generally, these systems include solar panels and inverters but often add battery storage components to supply electricity during nighttime hours. Off-grid system owners may also elect to purchase and use DC appliances rather than AC appliances. This reduces the amount of energy that must be converted from DC to AC and minimizes the loss of energy due to inefficiency in inverters.
Because the utility grid does not supply or supplement electricity to off-grid homes, the design process requires special attention to ensure adequate power is available. Many resources exist for calculating electrical loads and for sizing systems appropriately. Adding battery storage to the system entails balancing electrical loads between household demand and battery charging demand. Battery charging adds other components to protect batteries and extend their useful life.
Including solar energy as a part of home electrical design is becoming a more popular practice over time. Advances in the technologies that enable these systems and declining costs of components are making solar energy a more sensible and attractive option. Understanding some of the differences between on-grid and off-grid systems can help prospective homeowners decide if solar energy will be part of their new home.