How Does Solar Power Feed Back Into The Grid?


Solar power is one of the most promising technologies to fight climate change. However, there are a lot of technical questions that most consumers do not know the answer to. One of these is how does solar power feed back into the grid. In this post, we will answer that question.

Solar panels that produce direct current electricity is transformed into alternate current electricity, allowing the grid to be powered with the electricity. These systems are connected not only to the home but also to the grid. When there is excess power, this will go back into the grid.

But there is so much more to consider than just this. If you are interested in how this occurs in detail, keep on reading.

How is energy produced originally?

Each solar panel is a part of a much larger system that leads to the production of said energy. The sun is made up of light particles called photons, which goes through a process within the solar panel which produces electricity in the form of a direct current, which is usable and is transduced into other energies, whether that is in the form of heat, sunlight or anything in between. Thus, the energy from the sun is used to power your household appliances, and this is facilitated by a scientific transduction process, which occurs within the solar panels themselves.

But how does this process work? Solar power is converted into electricity, which gets fed into the inverted. This inverter is usually installed as close as it can be to your electric meter so that you can avoid any loss of power. However, it should also be kept cool and this is the priority for the inverter. If you can get in a cool place next to the meter, this is the ideal solution.

If you want to learn a bit more about where to place your inverter, be sure to check our article “Where Should I Place my Solar Inverter?“.

For the most part, you can get enough energy from your solar power system to power your house. Some extra energy is stored, but anything beyond this goes back to the grid.

Cost of Solar Energy

In the past, getting solar energy was extremely expensive. This made investing in solar energy more daunting for customers. It is important to consider that while it is an investment up-front, solar energy can save you enough money that this becomes a worthwhile investment for you. The cost savings of solar can pay itself back in a short period of time. 

The good news is that the cost of solar power has significantly decreased in recent years, which does make this more appealing to potential customers. There’s also the fact that there are often rebates and incentives for getting solar that make getting solar even more appealing.

One incentive in the US is the Federal Investment Tax Credit (ITC), which is a nationwide incentive that has the goal of promoting renewable energy. Different locations have their own incentives and rebates that you can look into, making solar power more affordable.

How does energy transmit nationwide?

However, despite solar panels being for your use, they are also able to be used nationwide in a similar manner, meaning that your panels don’t only draw energy from the sun as a source but also from the national grid. It can act in two different ways, either as a donor or a receiver.

When it acts as a receiver, it is taking energy from the grid, but when it acts as a donor it is actually giving energy back to the grid, and this can be useful when your solar cells are producing a surplus of energy that may be useless for you.

This level of donation or reception is measured only by the need of your household and others. When you have a high enough level of energy you will produce the extra energy to the grid, but when you are not using energy, which may be due to certain factors affecting solar power generation, you begin to receive energy from the national grid. 

There is actually a benefit to the customer when you have solar energy that transmits excess power back to the grid. When this happens, your electric meter actually can cause the meter to spin backward. If this backward spin happens more often than you are using the electricity, you can get a credit on your electric bill. This credit can go towards a future bill, in case you need it. If at the end of the year there is an excess in the credits, this money is often just paid out to the customer.

Eventually, between this money and the cost savings of using a solar-powered electrical system, this can help you more quickly paying off your solar panels. This shorter payback period can make solar energy more appealing to consumers.

How is this constructed?

There is a specific type of system that requires this to occur. This requires a slightly higher maintenance cost, as more things need to be added to allow the connection to the national grid. Therefore, this direct connection that is produced allows this donation or reception of energy either from or to your solar panels, and thus your home as a whole.

This can be done by trusted providers, of which there is a variety to choose from online, each offering different deals and packages as a part of allowing them to input your inverters and other maintenance needs.

When linking to the national grid it is important to have installed power conditioning equipment to ensure that everything runs smoothly during energy transfer to the grid. This, however, must be done in a safe manner and must include safety equipment.

Along with this, it is extremely important to include measurement instruments, allowing a precise understanding of energy transfer and the need to either donate or receive. 

There may be a high level of maintenance required to introduce this new source of environmental energy usage to your home, but it is certainly worth it, and here is how it’s done.

Depending on the department you use and how this connects to the national grid, there will be quite a variety in the standards of connecting the lines to produce/receive the extra electricity for your home. This can include a variety of objects known as inverters, which measures your electricity donation. Thus, as aforementioned, allowing the measurements of the need to donate or receive energy.

There is a detailed process as to how grid conversion actually occurs. It really does depend on your voltage level as to what is necessary. However, small devices can run on low-level electricity, but some devices need more electricity in order to function.

This allows us to introduce the idea of inverters, which ensure that the energy from your system is not overloaded when you donate it to the national grid. It converts the electricity into something passable by the grid. The equipment necessary will match the requirements of the electricity released into the grid, allowing to flow freely into the grid. 

The Current Requirements

Although there are a variety of different ways to connect generation systems to the grid to and from your panels, there are some common requirements that are important to follow. These generally follow health and safety procedures to ensure that nothing goes wrong during connection. 

One of the biggest requirements to consider is the minimum sunlight requirements. It’s important that you can get enough sunlight to power your home and if you don’t have access to the right amount of sunlight, this may not be an ideal situation for you.

The solar expert can take a look at the space and help you understand how many panels and where they will need to go in order to get the amount of energy that you need. There are other legal restrictions, such as whether or not the property has historical significance and how the building is used. These are just a couple of additional requirements to consider outside of installation and safety procedures.

To ensure that you have met these requirements make sure that you are specific requests from your power provider. If they do not have an individual for these situations, it might be worth contacting the state energy office, or any other viable entity who can deal with this query for you.

The law in depth

We can also point to authorities such as the Institute of Electrical and Electronics Engineers, who have written a rule of law that can be generally applied to all systems connecting to the grid. The Institute of Electrical and Electronics Engineers (IEEE), which essentially provides legislative information on a variety of things including fuel cells and other forms of energy. This includes IEEE 1547-2003, which essentially underpins the technical requirements for grids to work properly. 

Additionally, you can also look at the National Electrical Code, also known as the NEC, which legislates on electrical equipment and its safety. But we can also observe other entities such as Underwriters Laboratories, who have developed a variety of legislation to regulate electrical equipment and systems.

Do I have to sign contracts?

If you would like to sign your solar panels up to the grid, you will need to sign an agreement with those who have provided your solar panels. So yes, you will have to sign a couple of contracts to ensure you can connect to the grid. These contracts can include but are not limited to, liability insurance, and payment fees. Liability insurance essentially ensures that those who provided the solar power are not suffered in any way shape or form by faults with the solar panels. 

With Liability Insurance, you may be required to have a specific amount of insurance to ensure that your provider is not negatively damaged. This, however, does depend on the provider you choose. Therefore, they will not be liable for any damages that arise from your system.

You may also be charged some miscellaneous charges, and these can range from maintenance to upkeep when you decide to connect your solar panel to the grid. Once again, make sure you ask your energy supplier about any possible nasty costs to avoid for the future.

What are the laws around donating and accepting energy to/from my solar panels?

When you connect your solar panels to the grid, as aforementioned, you may either use too much energy or not enough, allowing reception and donation of electricity generated from your solar panels. 

This whole process is essentially covered by The Public Utility Regulatory Policy Act of 1978. This means that those who provide power have to buy extra electricity from your solar panels at the rate equal to the cost of the energy provider to essentially produce that power in the first place.

Continuing on from this when you connect your panels to your grid, there are certain rules you need to follow when it comes to the metering and the measurement of your energy. Some of these agreements include measuring the net metering total, along with the net purchase and the sale of energy generation.

Net metering essentially means the installation of a meter to record the electricity that you use and that you donate, this will therefore allow a calculation of the energy that you have used allowing an easy calculation of payments should you use that extra energy. But this also works the other way around as well, you will be paid for the excess energy you offload to the national grid itself, allowing easy measurements.

However, a net purchase agreement essentially puts in an extra meter. One of which will record energy entering the grid, whilst one will measure energy exiting the grid. In a similar way, you pay the rate for the electricity you use whilst the energy provider pays donated electricity. But with this method, do keep note that the finances you gain may not equal the finances you have to pay out, as this can be disproportionate.

Your first immediate query may be that some months generate more electricity than others, so it’s unfair that you will have to pay more on sunny days. Well, there are providers out there who will let you carry the energy finances over to the next months, essentially leaving a payment per annum, instead of an extremely disproportionate monthly payment.

What are the benefits of linking to the national grid?

The biggest problem with solar energy is that its reliability depends on the time that it is used. Notably, at night-time, solar panels are not the best at capturing any of those photons. But by linking to the national grid, you can usurp that unused energy from other electricity sources, to power your home through the night as well.

Chances are, that you own solar panels because you want to be more environmentally friendly and just by owning them and using solar energy you are certainly contributing towards this, but by linking your panels up to the national grid, you are also contributing even more to the environment, as you are saving the energy you produce by offloading all of your extra energy. Thus, it is an extremely great decision to make by enforcing this.

Additionally, as discussed later on, if there is a widespread grid failure that causes a heavy power outage, you can rest assured that your electricity will not be tampered with if you have a backup generator, allowing the constant production of energy.

Furthermore, this credit recognition from signing up with the national grid will give you a credit on your electric bill, but this can vary geographically and nationally, so do be sure to check with specific energy providers and your specific national grid to see the extent of the benefits that can be accrued from this.

But what can be some of the drawbacks to this?

In order to prevent injury to those who work on maintenance lines, or maybe by accident, the national grid may shut down once in a while. Thus, one of the largest drawbacks is that solar energy systems may shut down if a national power failure does ensue, you may not receive or be able to donate that extra necessary energy to keep your/other people’s appliances going. Meaning that too heavy reliability on the national grid may be a bad idea.

There may also be a high maintenance cost required to input this, but this really does vary from energy provider to energy provider, making it worthwhile to look into what you are getting for the cost that you are paying.

So, what should I take away from this?

When you connect your solar panels to the national grid you will need to make sure that you are contacting your energy supplier to ensure everything is done correctly and legally, ensuring all health and safety rules are followed, otherwise it could be done incorrectly and negatively affect you.

If it is done improperly, you may be hit with costs that you didn’t expect beforehand. But overall, this is an extremely good idea, as you will not only support other people by donating your excess energy but also allow others’ excess energy to be used by you, saving any potential waste.

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