Frequently Asked Questions

Renewable Generation at Your Home or Business

Are you interested in generating power from solar, wind or another renewable energy source at your home or business? Learn more below. If you need assistance, contact netmetering@idahopower.com.

The monthly electric bill for homeowners who install solar or wind may be lower because of the energy they receive from their system. But solar and other renewable generation systems can be a large investment, costing thousands – often tens of thousands – of dollars. So, while your electric bill may be lower each month, you won’t see a true return on your investment for years down the road. For example, if a Boise residential customer uses an average 1,000 kilowatt hours (kWh) a month and installs a 6-kW solar system, it could take 14 to 18 years to recover his or her initial investment in solar.

Many factors can affect the payback, including the installed cost per watt of the system, system design and energy production, and tax credit eligibility. A system’s energy production depends on the technology used, how the system is configured, as well as environmental factors. Wind production is affected by location, turbine height, and obstacles that interrupt wind flow, such as nearby structures or trees. Solar production is affected by the direction and tilt of the panels and shade. Also, electricity price changes will affect your estimation significantly. For example, Idaho Power’s residential rates have historically increased at a compound annual growth rate of 2.83 percent since 2003. Although this percentage adds context, it is not a reliable indicator or a guarantee of future rates.

Idaho has some of the lowest electricity prices in the nation, largely due to our clean, low-cost hydroelectric system. In states where electricity is expensive, an investment in solar on-site generation can have a quicker payback. In California, for example, solar install prices are only slightly higher than Idaho’s, but their electric utility prices are significantly higher. Therefore, residents of California, who choose to install solar can start saving money in less than 10 years.  Idaho Power customers enjoy lower electricity prices, which usually means a much longer period to recover an investment in solar.

Comparing identical energy use for San Jose and Boise
illustration of a house with a palm tree in the front yardSan Jose, California illustration of a house with a pine tree in the front yardBoise, Idaho
Average monthly electric use: 500 kWh 500 kWh
Average monthly bill: $113 $45
System size to offset 99% of use: 3.88 kW 4 kW
System net cost after tax credit: $11,000 $9,300
Estimated payback/break-even: 8 years 19 years
Total 20 year savings after payback: $19,500 $700

Sources: Project Sunroof and PVWatts Calculator

Currently, solar photovoltaic (PV) is the most common choice for those who generate their own renewable energy. However, Idaho Power’s net metering tariff allows customers to connect solar, wind, small-scale hydro and other renewable technologies. Learn more at idahopower.com/netmetering.

Before you decide on a size, consider taking advantage of Idaho Power’s energy efficiency programs to help lower your overall energy use. Reducing your energy needs may allow you to install a smaller system and save money. Information can be found at idahopower.com/save.

The size of the system depends on many factors including the type of technology, the available space and how much energy your home or business uses. Your monthly electric bill shows your usage for the past 12 months and can be accessed through My Account, Idaho Power’s online account portal. My Account is available at idahopower.com. For customers interested in solar, visit idahopower.com/solar for calculators to help estimate system size and costs.

The energy generated varies by the type of system and depends on such factors as technology, weather, location and directional orientation. PVWatts Calculator is an online tool developed by the federal government for estimating solar generation based on location, geographic weather patterns and system design. Simply input your city, solar size in kilowatts (kW) and the calculator will estimate solar electricity generation by month and 12-month total. Visit PVWatts Calculator at pvwatts.nrel.gov. Compare the PVWatts estimate to your 12-month historical energy use, which you can find on My Account at idahopower.com. If you decide to move forward with purchasing an on-site renewable generation system, a professional installer can help estimate potential generation from different systems.  Be sure to compare the installer’s estimated solar generation with the information provided by PVWatts Calculator.

For a solar array, each kilowatt (kW) of solar photovoltaic generation capacity requires about 100 to 200 square feet of roof or ground area depending on the efficiency of the panels.

For a wind turbine, the space depends on the type and height of the system installed. A general rule of thumb is the turbine generator should be 20 feet above the top of anything within 300 feet of the system. Turbines should be erected away from structures to minimize the risk of falling on buildings during strong winds. The minimum distance between turbines and structures is typically equal to the combined height of the tower and blades, known as the “fall distance.”

Most homeowners with on-site generation connect to Idaho Power’s electrical grid to ensure reliable, consistent electricity. The wind doesn’t always blow. Solar panels only produce when the sun is out. Even then, the panels may not produce enough energy to meet the home’s energy needs at all times. The grid lets solar customers draw power at night when there is no sunshine, during a cloudy day, or anytime they need more electricity than their system is generating. Also, most customers with on-site generation rely on the grid for the rush of power needed to start up large appliances like air conditioning units. Without the grid, the average solar or wind generation system can’t supply enough instantaneous power to turn on these large appliances. For these reasons, homeowners with on-site generation rely on Idaho Power’s electrical grid every hour of every day.

The graph below shows a full day’s meter readings for a sample home with an on-site solar generation system connected to Idaho Power’s electric grid. One example is from August when the days are long and solar panels are at their peak generation. The other example is from December, when solar panels typically produce less than half the energy than they do in July and August because of the shorter days in winter.

The red line indicates zero kilowatt-hours. The yellow shading shows the times that the home’s solar is generating more energy than the home is using. During this time, excess energy is delivered to the grid. The blue shading shows when the home needs more energy than solar can provide, and the home is drawing energy from the grid.

 

a graph showing the hourly kilowatt-hour meter read on a long and hot summer day

*For simplicity, the chart shows a pure yellow color. However, the home may still rely on the grid even when solar is at its midday peak. For example, when a cloud goes by or a large appliance needs a boost, the grid is there to meet the home’s energy needs.

Generally, no.

Having power when the grid is down generally requires battery backup. Inverters are the part of a typical solar or renewable system that convert DC power to usable AC power. The vast majority of inverters are grid-connected and work only if the electrical grid is functioning normally. If the grid experiences an outage, the inverters sense the abnormality and will stop interacting with the grid. This helps keep work crews safe and the grid stable.

A small number of customers connect to the grid and have a battery backup.  This allows them to use energy stored in the batteries while the power is out. Battery backup systems will add significant cost to the overall system.

No. However, there are federal and state tax incentives and loan programs that can help with financing on-site renewable energy sources. Upfront cash payments will have a shorter payback period than financing with a loan. The Idaho Office of Energy and Mineral Resources has information on financing options at oemr.idaho.gov. For Oregon customers, visit the Oregon Energy Department at oregon.gov/energy. The Database of State Incentives for Renewable Energy (DSIRE), funded by the U.S. Department of Energy, also lists incentives for renewable resources by state at dsireusa.org.

 

There are three options for interconnecting renewable generation to Idaho Power’s grid:

Option 1: Net Metering: Net Metering is the most common avenue for Idaho Power’s customers to interconnect renewable generation to offset their own energy consumption. Idaho Power’s Net Metering tariff allows customers to install small-scale renewable generation projects on their property and connect to Idaho Power’s electrical grid.

Option 2: Schedule 86: Schedule 86 is available to generators who wish to receive financial payment for their production at market-based rates. Under Schedule 86, generation from installed renewable systems is separately metered, and sellers receive financial payment for each kilowatt-hour (kWh) of energy produced. The price paid per kWh is based on market prices recorded within the same month.

Option 3: Energy Sales Agreement: Generators who wish to sell electricity to Idaho Power under a long-term contract can procure an Energy Sales Agreement, or ESA. Under the terms of an ESA, sellers are paid for each kWh of energy produced according to avoided-cost rates set by the Idaho Public Utilities Commission. In order to receive payment at avoided-cost rates, a generation unit is subject to strict performance requirements on a monthly basis. Due to the more stringent requirements, this option is not typically utilized by Idaho Power’s residential or business customers.

Do your research.

  • Visit idahopower.com/solar to find:
    • The Solar Checklist to navigate through your decision-making process
    • A link to a solar calculator for a general idea of cost and payback based on today’s rates
  • Visit idahopower.com/netmetering to find:
    • Rules for connecting on-site generation to Idaho Power’s electrical grid
    • Information on net metering billing and credits
    • Applications and forms
  • Register on My Account to view your past energy use and identify your energy needs

When you are ready to proceed, find an installer. Idaho Power recommends getting three bids. The Idaho Office of Energy and Mineral Resources has a list of installers.  We recommend verifying the installer’s estimates with the information provided above.

You have options when it comes to renewable energy and using energy wisely. We have programs and tools to help you decide which Green Choices are best for you.

Helpful Links

idahopower.com/greenChoices to see your renewable energy and conservation options

idahopower.com/solar for a starting point on your options and research

idahopower.com/netMetering for tariff information

idahopower.com Login to My Account for energy usage history

google.com/get/sunroof for an estimate on solar size, cost and payback

pvwatts.nrel.gov to estimate system size and energy output

oregon.gov/energy to find tax credits for Oregon residents

dsireusa.org a database of state incentives for renewables

oemr.idaho.gov/wp-content/uploads/2015.12.31_ID_Solar_Dev_Res.pdf for a list of solar installers