Wind and solar net-metering

On-grid wind and solar systems require Net Metering: a system that keeps track of the difference between the electricity you store in the grid and the one you take from it. If your system generates more electricity than you use, the electric meter will spin backward.

Note:
There is no difference between net metering for grid-tied PV solar and net metering for grid-tied wind power systems. The information presented below are valid for both systems, and for hybrid ones.

Net metering & Wind and Solar PV systems size

The size of your generating system doesn’t interfere with net metering. If you have a small system and your production is lower than consumption, you just have to pay the difference. If you have a large system and your production is higher than your consume, you can store the extra electricity on the grid (and eventually sell it).

Conditions & Net Metering

All residential users of small solar and wind energy systems (and hybrid systems) are eligible for Net Metering. Most residential PV solar and wind systems connected to the grid and using net metering, range between 2 and 4 kilowatts, but there isn’t usually a required minimum size. You just need to be connected to the grid. Law may demand the wind or solar system to be located on your property and that its capacity doesn’t exceed a certain limit.

Current electric meters

Most current residential meters are bi-directional, in other words, capable of measuring your electric outputs and inputs involving the grid and your PV solar or wind system. If this is your case, your meter is suitable for net metering.

But some companies may want demand two meters: one to measure the electricity that goes to the grid, and another to measure the other flow. Just contact your utility for information on this issue.

Net metering agreements

Net metering involves an agreement between you and your utility or electric provider. Typically the meter will be read once a month, and will show the net difference between the electricity you take from the grid and the one you store into it. And that’s that difference that you will have to pay (if positive).

In most states there are power companies (Electric Service Providers) and companies that distribute electricity (Local Distribution Companies), or simply a company that does both functions. Usually Electric Service Providers handle the Net Metering billing and accounting, while local distribution companies handle the technical stuff: connection of your PV or wind system to the grid, safety, inspections... Just contact these companies, demanding the agreement.

Selling energy to the grid

If your wind or PV solar system produces more electricity than you use, the utility or electric provider is not required to purchase the excess, unless otherwise agreed.

Typically, law do not required the utility to pay for possible excess generation, but some agreements might involve that payment – just contact different utilities or electric providers in your region, to see if anyone one buys excess generation.

Advantages of Net Metering

Net Metering has clear advantages: it’s a simple system, that allows an automatic way to store the electricity that your system generates and your are not using, and also a simple way to recover that stored electricity whenever your needs exceed your electric system production. All that without having to invest on an expensive storage system. Net Metering turns the investment on solar and wind power more competitive.

Eventually, it also allows you to sell part of your production, if it exceeds your global needs.

In some cases, you may also benefit from lower rates. If your wind or solar system generates most of your electricity needs, you may be charged with lower rates whenever your annual net consumption falls below the utility baseline limit.

Disadvantages of Net Metering

If your PV solar or/and Wind system meets the standards and typical performance, you will not be charged for fees, inspections or certifications. You just need to have a bi-directional meter (a simple and common type of meter that you probably already have).

However, in some cases, grid connections can be expensive, namely if you live in a remote place: running a power line between a remote site and the utility grid can amount to $15,000 to $50,000 or more per mile.

And obviously, net metering will make you dependent of external events and utilities decisions and politics.

Billing & Net Metering

The type of agreement between you and the utility may vary. The utility will read your meter monthly, and you will receive monthly statements with the amounts of electricity consumed and generated.

Annual billing is very common, but you may opt by monthly billing. Companies may or may not buy excess generations, depending on the terms of the agreements and the current practice of the electric providers and utilities.