If you are tired of being at the mercy of the energy markets with their price swings and budget busting rate changes,
then solar power is for you. Whether you are a residential consumer of electricity, a commercial or industrial business or a utility scale purchaser of electricity — technology, government support and regulatory policy is swinging heavily toward making solar power the smart play. Beacon Renewable Energy can make your transition to
renewable energy easy and affordable.
We know you have questions. We’ve compiled many of the most frequently asked for your convenience below. We’ve also provided you with a basic glossary of solar related terms to the right. For another excellent resource for understanding solar and related terms please vist Sun Edison’s site by clicking here.
What is photovoltaic (solar electricity), or PV?
The word itself helps to explain how photovoltaic (PV) or solar electric technologies work. The word has two parts: photo, which means light, and volt, a measurement unit. The literal translation is light-electricity. That is precisely what photovoltaic (PV) panels do, convert light energy to electric.
How do solar photovoltaic cells work?
In layperson terms, photovoltaic cells are comprised of a semiconductor material such as silicon. Added to the silicon are the elements phosphorous and boron which create conductivity within the cell and activate the movement of electrons. The electrons move across the cell when activated by the sunlight's energy into the electrical circuit hooked up to the solar panel.
How much does a solar electric power system cost?
In both residential and commercial based solar electric systems there are multiple variables that influence the cost. They include but are not limited to the amount of utility grid power to be offset, the selected type of system and mounting options which are influenced by type and condition of roof.
Are there rebates and tax incentives available?
Yes, there is a 30% federal government tax credit towards installation on solar PV systems on commercial buildings. There are environmental and state govt. credits such as Solar Renewable Energy Credits (SRECs) that can be sold based on the electric production of system. For more info click here.
What’s the difference between solar photovoltaic and solar hot water systems?
While both types of solar systems capture energy from the sun, solar photovoltaic systems use photovoltaic panels to produce electricity. Solar hot water, or thermal, systems capture sunlight to heat water for domestic use, to heat a swimming pool, or for a radiant heating system.
Can I use solar power to heat my home?
Absolutely! Radiant heating applies solar thermal technology. Transferring solar energy through pipes into an under floor radiant heating system is a wonderful way to stay warm. Radiant floor systems are typically 40 percent more efficient than their forced air counterpart and can be zoned to match thermal comfort to each room.
How much maintenance do solar energy panels require?
Solar photovoltaic panels require little maintenance. It is, however, important to place panels where they will remain clear of shade and debris. Thus you will have to wipe them off if too much snow or leaves fall on them. Solar hot water collection arrays don't need much attention either. It does help to periodically use a window wash brush, biodegradable soap, and water to clean the tubes.
Can I use a financing system?
Yes. There are several financing options available. For residential consider using using a home equity loan for the purchase and installation costs of a solar photovoltaic or solar hot water system to take full advantage of federal tax deductions. Solar energy systems are viewed as a major home energy savings upgrade and there are financial tools out there that reward you for your efforts. For commercial, educational and government customers there are Power Purchase Agreements (PPAs) that provide upfront financing of a solar electric system in exchange for agreements with customers to buy the resulting power.
Do I need special insurance requirements?
If you are buying a PV system for your home or bsuiness, standard insurance policies usually suffice to meet electric utility requirements. For a grid connected PV system, your electric utility will require that you enter into an interconnection agreement. Usually these agreements set forth the minimum insurance requirements to keep in force.
Will I need a building permit to install a solar energy system in my home?
Yes. You'll need to obtain building permits to install a solar photovoltaic or solar hot water system. Similarly, building, electrical, and plumbing codes also apply. That said, residential solar power systems do not use "radical" building techniques and most jurisdictions have building codes that fully embrace solar energy technology. Solar professionals will roll the price for permits into their cost estimate.
How can I calculate the cost and payback time from a solar power installation?
An important point to consider when buying a solar electric or solar thermal system is that you are purchasing 25 or more years of energy up front at a fixed cost. You can estimate how much a solar electric or solar hot water system may cost if you determine your current energy needs and costs and compare against your future anticipated use. Once you have a sense of how much energy you use, you can evaluate the cost of purchasing and installing one or both of the technologies. Luckily in today's market you can take advantage of multiple federal, state, and local tax credits, rebates and other financial incentives that create attractive and competitive prices for solar PV and hot water systems.
What components do I need to install a grid-tied solar electric system?
You will need a photovoltaic array to capture the sun's energy, an inverter to convert the direct current (DC) produced from the photovoltaic cells into alternating current (AC) used by your home, and a house utility meter – called a net meter – that can record both the electricity produced from your home's power system as well as any power you may use off the grid. These three system components are then connected through a series of wiring. The photovoltaic panels are secured to your roof with panel mounts or are installed on poles that can be adjusted for sun angle.
What is a net meter?
Some utility companies have net metering programs which further enhance the economics of PV. When a PV system generates more electricity than needed, the excess goes to the utility grid which spins the meter backwards. This excess power can then be sold back to the utility or traded for future credit on the host’s utility bill.
Do I need battery backup for my solar panels?
Probably not – a backup battery bank can add as much as 25% in cost to a residential solar PV system. It's not necessarily more efficient either – a same sized solar array will yield about 7–10% less energy if it's battery-tied than its grid-tied counterpart. Though you will remain tethered to your local utilities' grid, you will not have to worry about not generating enough power. You also gain the advantage of offsetting rising utility costs. Most solar photovoltaic experts do not recommend adding a backup battery system unless there is concern about a long utility outage or the residence is in a remote location.
How much space do I need for a solar photovoltaic system? In bright sunlight, a square foot of a conventional photovoltaic panel will yield 10 watts of power. That's a helpful rule of thumb for calculating a rough estimate of how much area you might need. For example, a 1000 watt system may need 100 – 200 square feet of area, depending on the type of PV module used.
How much shading is too much for solar photovoltaic panels?
Unfortunately shading a photovoltaic system dramatically decreases its output. Just shading the bottom row of wafers alone amounts to an 80% reduction in efficiency. So above all, don't shade your array!
Do I need to have south facing exposure to have a solar energy system?
Although southern exposure increases the effectiveness of both commercial and residential solar power systems, solar power can still work without having south facing exposure. Seek advice from a professional solar designer or installer to ensure success.
Glossary
- Alternating Current (AC)
- An electric current that alternates direction between positive and negative cycles, usually 50 or 60 times per second. Alternating current is the current typically available from power outlets in a household.
- Ampere
- A measure of electrical current. It is the number of electrons flowing past a given point in an electrical conductor in a given amount of time.
- Amorphous Silicon
- A form of silicon that is noncrystalline. Also called thin film, it is different from regular silicon used in panels and chips, in that it is more flexible. It can be deposited in thin (measured in micrometers) layers by a number of methods.
- Base load
- minimum energy level a company provides its customers on a constant basis.
- BTU
- British Thermal Unit-the amount of heat energy needed to raise the temperature of one pound of water by one degree Fahrenheit.
- Calorie
- Metric thermal unit: the amount of heat energy needed to raise the temperature of one kilogram of water by one degree Centigrade.
- Concentrator
- Usually a reflective mirror that focuses and enhances the sun's rays onto a photovoltaic surface. This may sometimes refer to a lens with the same purpose.
- Competitive Power Supply
- Any company that (usually generates then) sells power.
- Connection Charge
- Fee demanded by utilities for the cost of hooking up new service.
- Conservation
- Achieving the reduction of energy usage through increased efficiency or reduced waste.
- Deep cycle battery
- A battery designed to tolerate up to 80% discharge of its capacity.
- Depth of discharge (DOD)
- the amount of energy (expressed in percentage of its rated capacity) withdrawn from a battery, a battery bank or a cell.
- Direct Current (DC)
- Electric current flowing in one direction in invariable amperage. This is most often associated with battery power.
- Distributed Generation
- (Distributed Energy Resources) Electricity that is provided by small power generators located at or near end users.
- Energy Efficient
- A qualification of electrical products, in which they achieve an appropriate ratio of energy usage to work-type output. For example, an energy efficient light bulb will use most of the input electrical energy to produce light, not heat.
- Evacuated Tube
- Used in solar thermal collectors, these are glass absorber tubes with the air evacuated and through which collector fluids (water or perhaps glycol) flows.
- FERC
- In the USA, The Federal Energy Regulatory Commission is an independent government agency that regulates rates charged by public utilities. Its jurisdiction is somewhat disputed but it includes the sale of electric power for resale.
- Flat Plate Pumped
- Most widely used among solar thermal collectors, this typically consists of a metal frame, glazing, absorbers (usually metal), and insulation with a pump liquid (typically glycol) as the heat-transfer medium: used in water heating applications.
- Generation
- The act of producing electricity.
- Grid
- The electrical distribution system, as laid out by wires, conductors, stations, etc.
- Grid-Interactive System
- See Utility interactive system. Also called a Grid-inter-tied system.
- Insolation
- Solar radiant energy impinging on the earth in any given region or area.
- Inverter
- A device that changes direct current (DC) into alternating current (AC).
- Kilowatt (kW)
- One thousand watts of electricity (See Watt).
- Kilowatthour (kWh)
- One thousand watthours.
- Lead-acid battery
- Slightly larger than a car battery, these have internal plates made of lead or a lead alloy, surrounded by a sulfuric acid electrolyte. Car batteries are made with softer plates. Lead-acid batteries are commonly used in solar and wind energy systems.
- Line wire loss
- Voltage or power lost due to the resistance of wires in an electric circuit. Power loss is often proportional to wire length and is far greater in DC than AC.
- Load
- the electricity required and used by any single or collection of electrical item(s).
- Load Profile
- Collected information on a customer's usage over a set period of time. It is sometimes shown as a graph on the customer's bill.
- Maximum power point (MPP)
- The voltage at which a PV array is producing maximum power.
- Maximum power pointtracker (MPPT)
- A power conditioning unit that increases the power of a PV system by ensuring operation of the PV generator at its Maximum Power Point (MPP). The ability to do so can depend on climate and the battery's state of charge.
- Megawatt (MW)
- One million watts of electricity (See Watt).
- Net Metering
- An arrangement permitting a household or business (using a utility meter that spins forward and backward, reading both inflows and outflows of electricity) to sell excesses of power generated over its load back to the utility supplier to offset costs.
- Off Peak/ On Peak
- Times when energy demand and price is low (off-peak) or high (on-peak)
- Parabolic Dish
- A high-temperature (above 180 degrees Fahrenheit) solar thermal concentrator, generally bowl-shaped, with two-axis tracking.
- Parabolic Trough
- A high-temperature (above 180 degrees Fahrenheit) solar thermal concentrator with the capacity for tracking the sun using one axis of rotation.
- Passive Solar
- A system in which solar energy alone is used for the transfer of thermal energy. Pumps, blowers, or other heat transfer devices that use energy other than solar are not used.
- Peak load
- The maximum demand for energy on a utility system which has to be met by the utility's power generating capacity.
- Peak Watt
- A manufacturer's unit indicating the amount of power a photovoltaic cell or module will produce at standard test conditions (normally 1,000 watts per square meter and 25 degrees Celsius).
- Photovoltaic (PV)
- the production of electricity from light. See also Solar cell.
- Photovoltaic cell/Solar Cell
- A device made of silicon and semiconductor materials, producing electricity when exposed to sunlight. Movement of electrons is produced by fabrication of adjacent layers of materials with different characteristics.
- Power
- The rate of doing work, expressed in watts (W). For example, a generator that is rated at 750 watts will be able to produce that amount of power continuously.
- Public Utility Regulatory Policies Act (PURPA)
- In the USA only: this is part of the National Energy Act. PURPA is intended to encourage the conservation of energy, more efficient use of resources, and equitable energy rates. Some important measures relevant to The Solar Guide include sections on net metering and incentives for renewable energy.
- Qualifying Facility
- A small power production facility that meets ownership, operating, and efficiency criteria established under the Federal Energy Regulatory Commission (FERC) and the Public Utility Regulatory Policies Act (PURPA).
- The Renewable Portfolio Standard (RPS)
- In the USA, this is a mandate requiring that renewable energy provide a certain percentage of total energy generation or consumption.
- Resistance
- Property of a material that resists the flow of electrons when a potential difference is applied across it. This is measured in Ohms. Resistance is the quality that causes electricity to produce light in a filament or heat in an electrical heater of any kind.
- Resistor
- Any electronic component that restricts the flow of electrical current in circuits. These are often used intentionally to produce heat or light (e.g. a stove element or a light bulb filament).
- Ribbon Silicon
- A type of single-crystal silicon that produced in sheets or ribbons.
- Silicon
- Semiconductor material made from silica, purified for photovoltaic applications.
- Single Crystal Silicon
- A very pure (and very expensive) form of crystalline silicon.
- Solar cooling
- The use of devices that absorb sunlight to facilitate convection, similar to processes used in gas-fired refrigerators.
- Solar electricity
- Electricity produced in photovoltaic processes, by action of sunlight.
- Solar energy
- The radiant energy of the sun. This can be converted into usable forms of energy, such as heat or electricity.
- Solar modules/Panels
- Large collections of solar cells that can produce electricity at a worthwhile rate. These are packaged for end use and suited to be incorporated into solar energy or solar electricity) systems.
- Solar Photovoltaic
- The process of converting the sun's energy into electricity.
- Solar Thermal collector
- A device designed to collect solar radiation and convert it into thermal energy (usually to heat water).
- Solar Thermal energy systems
- Systems that collect the sun's energy to produce heat, usually to heat water.
- Stand-Alone system
- A solar PV installation that is not connected to a utility power line (the grid).
- Thermal
- Pertaining to heat gain and heat retention.
- Thermosiphon System
- A type of solar thermal collector (with water heated directly) in which circulation through the storage loop is provided solely by the heating of the water.
- Thin-Film Silicon
- Most often this is amorphous (non-crystalline) material used to make photovoltaic (PV) cells.
- Tracker
- in solar electric and solar thermal systems, a device used to track the sun.
- Utility-Interactive System
- Any solar PV installation that is connected to and interacting with a utility power line.
- Volt
- The unit of electric potential (intensity) and potential difference. It is also a relation of current to resistance: i.e. 1 volt is the potential difference across a resistance of 1 Ohm when a current of 1 Amp is flowing.
- Voltage drop
- The voltage lost along a length of wire or conductor due to resistance. The voltage drop is calculated using Ohm's Law. Voltage drop is also measured for resistors.
- Voltage regulator
- A device to control the operating voltage of a photovoltaic array.
- Voltage
- The measurement of the "intensity" of electricity.
- Wafer
- Raw material for a solar cell, a thin sheet of crystalline semiconductor material is made by mechanically sawing it from a single-crystal boule or by casting it.
- Watt (Electric)
- The basic unit of electrical power. It is only ever defined in reference to current and intensity — as in 1 watt equals 1 ampere of current under pressure of 1 volt.
- Watt (Thermal)
- A unit of power in the metric system, expressed as energy per second.
- Watthour (Wh)
- A measure of energy, equal to 1 watt of power used or received by an electric circuit steadily for the duration of 1 hour.