f you are a lucky residential solar system owner, you must make sure your utility solar meter suits it. Solar energy meters have to measure not only the amount of electricity your home pulls from the grid but also the amount it exports to the grid.
How is solar energy sent to the grid measured?
Let's start with the basics: what is an electric meter actually? In simple terms, it is a piece of equipment that calculates how much electricity we consume. It operates by measuring the instantaneous voltage (volts) and current (amperes). Voltage multiplied by amperage gives us an electrical system power measured in watts.
Electrical usage, in turn, is measured in kilowatt-hours (kWh). Kilowatt-hour is a record of the energy provided by a thousand watts in one hour. For example, running a 100-watt lightbulb for 10 hours takes one kilowatt-hour of electricity
Is analog meter right for solar?
An analog meter is the oldest way of measuring electricity consumption. It uses an aluminum disc that rotates responding to magnetic fields created by the current flow which moves through two conductor coils. The speed of the rotation is proportional to the power flow through the meter.
These meters are increasingly being replaced by newer digital alternatives. A primary reason for this is that analog meters function well when installed but their accuracy degrades over time, as the dials tend to loosen up.
But when it comes to solar, the problem is much bigger than that. Analog meters offer limited functionality, as they only measure kilowatt-hours of electricity you pull from the electrical network. But with solar systems, you will also need to measure how much electricity is being sent to the grid. Apart from this, solar generation requires more tracking and data analytics in real-time to better manage solar power generation.
Newer digital options for solar
Digital meters use more complex technology. Older types measure the amount of electricity flowing from the grid into your home and then use analog-to-digital converters to translate an analog signal to a digital form.
Newer meters which are much better suited for solar come with alternating current sensors that detect the current and generate a signal proportional to it. Such a meter has higher accuracy in capturing the electricity flow generated by a solar system.
A digital solar meter has to be bi-directional. This means it has to measure electricity going in two directions: from the solar system to the grid and from the grid to the consumer.
An alternative to a bi-directional solar meter is dual metering when two separate one-directional meters are used. One of them records the electricity received from the electrical system and the other records the electricity that is fed into it. These meters are popular with solar owners who have different rates for energy pulled from the grid and exported to it.
However, traditional digital solar energy meters aren’t the best option available in the market today. They capture only passive accumulation, that is, the electricity that has been consumed since the last manual reading around 3 months ago, and do not give any details on electricity consumption, which is especially useful for consumers who own solar power systems.
Smart solar meters
A smart solar meter is currently considered the best metering solution which offers closer consumption monitoring. It doesn’t need to be read manually, as it records electricity use in at least 30-minute intervals and automatically sends the data to a utility company. Another major advantage is that solar owners get access to detailed real-time information regarding electricity usage, which helps them control solar generation and save on utility bills. The smart solar meter also monitors the supply for malfunction and automatically informs the energy provider in case of problems.
One more advantage - with a smart solar meter a consumer can get a flexible pricing plan which implies that the cost of electricity changes according to what time of the day it is used. This means you will be able to cut your bills by using energy at off-peak hours.
How do I get a solar meter?
Once you have your solar system installed, you should contact your electricity retailer. They will tell you whether your meter needs upgrading to measure the solar power and whether they offer smart solar meter installations and upgrades. They will also inform you of any changes to your electricity supply contract and billing rates caused by your switch to solar.
In case you have a basic accumulation meter, it will have to be replaced with a smart solar meter capable of tracking how much electricity you are sending to the grid as well as pulling from it. If you already have a smart meter, it will have to be reprogrammed to ensure it's compatible with your solar system.