To help examine whether a home solar electrical system will work for you, you ought to think about the following:
- Your offered solar resource– do you have clear and unobstructed access to sunlight for most or all of the day, throughout the year?
- The system size– do you have a roof or area big enough to accommodate it?
- The economics– is it worth the financial investment?
- Local licenses and covenants– exist any concerns with installing a system?
EXAMINING YOUR SITE’S SOLAR RESOURCE
The solar resource throughout the United States is adequate for solar electrical systems– also known as photovoltaic (PV) systems– because they can use both direct and scattered sunlight. Nevertheless, the amount of electrical energy produced at a specific site depends on how much of the sun’s energy reaches it. Thus, PV systems work most efficiently in the southwestern United States, which receives the best quantity of solar energy.
Before you purchase a PV system, you will want to make certain your site has enough solar power to fulfill your electrical energy requires efficiently and financially. Your regional system provider can carry out a solar site analysis for you or reveal you how to do so on your own.
When assessing your site, you’ll also need to consider both the geographic orientation and the tilt of your solar panels– PV modules– as both can impact your system’s efficiency.
THE ECONOMICS OF A SMALL SOLAR ELECTRIC SYSTEM
The economics of a home solar electric or PV system are figured out by both the capital and operating costs. Capital expenses consist of the initial costs of developing and installing a PV system. Operating expenses include the costs connected with maintaining and operating the PV system over its beneficial life.
The aspects that impact both capital and operating expense include:
- System elements
- System size
- Whether a system is grid-connected or stands alone (off-grid).
- Solar resource at your area (amount of sunshine).
Prior to choosing system parts and sizing a PV system for an existing home, you need to examine your energy intake patterns and try to minimize your home’s electrical power use.
You can start by carrying out a load analysis, which includes these jobs:
- Looking at your energy costs over the previous year.
- Determining energy intake.
- Acknowledging consumption patterns.
- By understanding your “energy habits” and becoming more energy effective, you can reduce the size of the PV system you’ll need, reducing both your capital and operating costs.
If you’re designing a new home, you need to work with the contractor and the solar expert to incorporate your PV system into your whole-house system style– an approach for constructing an energy-efficient home.
PV COST CONSIDERATIONS
Ask your PV provider how much electrical energy your brand-new PV system will produce annually (determined in kilowatt-hours) and compare that number to your yearly electricity usage (called need) to obtain a concept of how much you will save. As a guideline, the cost per kilowatt-hour goes down as you increase the size of the system.
You ought to likewise compare the purchase price of utility-generated electricity to the higher expenses of smaller sized PV systems. PV-generated electrical energy is generally more expensive than standard, utility-supplied electricity. However, these costs will vary by geographical area.
Solar refund programs, subsidies, and other rewards can assist make PV more budget friendly. Tax incentives may consist of a sales tax exemption on the PV system purchase, a real estate tax exemption, or state personal earnings tax credits, all of which offer an economic benefit to customers by decreasing high capital costs.
Some solar rebate programs are capped at a certain dollar amount. Therefore, a solar electric system that matches this cap maximizes the benefit of the solar rebate.
Numerous property owners use PV systems since other considerations– such as ecological advantages and energy independence– tip the balance in their favor.
PERMITS AND COVENANTS
Prior to buying a home solar electric system, research your local permit and neighborhood covenant requirements.
You will most likely have to obtain permits from your city or county building department. These consist of a building permit, an electrical permit, or both. Normally, your PV provider will look after this, rolling the price of the permits into the overall system price. Nevertheless, in some cases, your PV service provider might unknown how much time or loan will be involved in acquiring a permit. If so, this task may be priced on a time-and-materials basis, especially if extra drawings or calculations should be supplied to the allowing firm. In any case, make certain the permitting expenses and responsibilities are attended to at the start with your PV supplier prior to setup starts.
Code requirements for PV systems vary somewhat from one jurisdiction to the next, however many are based upon the National Electrical Code (NEC). Article 690 in the NEC define requirements for creating and setting up safe, trustworthy, code-compliant PV systems.
If you are among the first people in your community to install a PV system, your local structure department might not have experience in approving one of these systems. If this holds true, you and your PV provider can speed up the procedure by working carefully with building authorities to educate them on the technology.
If you live where a house owners association need to authorize a solar electrical system, you or your PV provider will likely have to submit your plans and get approval prior to you start installing your PV system. Nevertheless, some state laws specify that you can set up a solar electrical system on your home.
For more details on state and community codes and requirements, see planning for a little renewable resource system.
STAND-ALONE SMALL SOLAR ELECTRIC SYSTEMS
A stand-alone home solar electrical or PV system operates “off-grid”– it isn’t really linked to an electrical power distribution grid operated by an energy.
A stand-alone PV system makes sense if any of the following apply:
- You reside in a remote area where the system would be more cost effective than extending a power line to a grid.
- You’re thinking about a hybrid electrical system– one that uses both a PV system and a small wind electrical system.
- You require minimal quantities of power; e.g., watering control equipment and remote sensors.
- Anybody can make the most of outdoor solar lighting– a stand-alone PV application.
For more information, see Stand-Alone Home Energy Systems.
GRID-CONNECTED SMALL SOLAR ELECTRIC SYSTEMS
A grid-connected home solar electric or PV system gets back-up power from an energy’s grid when the PV system is not producing adequate power. When the system produces excess power, the utility is needed to buy the power through a metering and rate plan.
Net metering is the best arrangement. Under this plan, the power supplier basically pays you market price for the electricity you feed back into the grid.
For additional information, see Grid-Connected Home Energy Systems.
ESTIMATING ENERGY COST SAVINGS FOR NET-METERED PV SYSTEM
Utilizing the equation below, you can approximate the yearly electrical power production and electric costs cost savings for a grid-connected home solar electrical system with a net metering arrangement.
- Identify the PV system’s size in kilowatts (kW). A typical variety is from 1 to 5 kW. This worth is the “kW of PV” input for the formula below.
- Based on your geographical location, pick the energy production factor from the map below for the “kWh/kW-year” input for the list below equation.
Electricity production from the PV system = (kW of PV) × (kWh/kW-year) = kWh/year.
You can calculate your annual electric costs savings using the list below formula. Keep in mind that the property rate should remain in dollars per kWh; for instance, a rate of 10 cents per kWh is input as $0.10/ kWh.
Electric costs savings = (kWh/year) × (Residential Rate) = $/ year.
( To determine your regular monthly electrical expense savings, divide the final number above by 12.).
For instance, a 2-kW system in Denver, CO, at a domestic energy rate of 7 cents/kWh will conserve about $266 each year: 2 kW × 1,900 kWh/kW-year × $0.07/ kWh = $266/year (or $22.17/ month).