Connecting to the Grid for smaller wind systems usually means Net-Metering – producing Energy each month not greater than your monthly consumption.
For larger wind projects (Wind Farms) connecting to the grid is a vital consideration for exporting electricity. This is your Utility Interconnect, and will be covered by an Interconnection Agreement with your Utility.
Check with your utility to determine their specific Net-Metering policy, there are often limits, usually defined by Power Rating and is typically 25 Kw.
Net-metering allows an electrical consumer to install a qualifying facility (QF) to produce clean electricity that is fed back into the grid. When you define your Net-Metering system the first step is to check with your specific Electric Service Provider (ESP), your utility, and determine their “Net-Metering Interconnection Policy”.
If your Utility is an IOU (Investor owned Utility) then the Federal Law known as the PURPA ACT (Public Utility Regulatory Policy Act) of 1978 grant electrical consumers the right, in principle to produce electricity onsite, and feed that energy back into the Electric Grid to off-set their energy consumption.
Your Wind Project must meet the standards of the National Electric Code (NEC) to be granted the status of “Qualifying Facility” (QF). This is your goal.
Sizing your Wind Generator Grid-Tie Net-Metering System is done by defining your Energy Load. For an existing facility your electric bill will list your current, monthly, and average KWH electrical draw. Your Energy Load will be your Kilowatt-hour (KWH) consumption per unit time – usually Monthly and Annually.
HINT: Find kWh per month load at your site and determine the total kWh per month consumed, and Total Amount Paid for this energy. This will be used in the economic analysis of your project.
Example: Residential Net-Metering Wind Power System
Looking at your electric bill, in this example, you determine your Monthly average Energy Consumption is 1,300 Kwh during the winter, and 1,800 Kwh per month during the Summer. Net-Metering laws allow you to earn full retail value (for Residential loads), and full retail, or near retail, rates for Commercial sites. Your specific Utility will have their own policy, and its vital to ask your local utility regarding their Net-Metering policy, and/or requirements.
HINT: Most utilities will require a bi-directional electrical meter to measure the Kwhs that your wind generator exports to the grid.
Using our Residential example, we consider the Energy Output of different manufacturers and choose an ARE442 Grid-Tie Wind Generator power rated at 10 Kw. We choose this Machine NOT by the power rating, but by using the Manufacturers Energy Output Chart, by finding the average Energy Production for a given Wind Speed: specifically your site’s average Wind Speed. Using a Wind Resource Chart you want to determine your Average Wind Speed at 20 meter and 50 meter heights.