Solar Systems Have A Great Potential
With new exciting technologies improving the performance of electricity generated from solar power appearing frequently, it seems like we could soon rely on this sustainable source of electricity to power our lives.
The truth is that the ability to harvest the sun’s power is only half of the story. For us to rely on this source all day long, we need a way to store this energy. For this reason, batteries for home solar systems are a topic worth discussing.
It doesn’t matter if your goal when installing solar is to save on utility bills or to become more self-sufficient and resilient it is likely that you will need to consider adding storage capacity to your system at one point or another.
What is a battery
A battery for our application is a device that can store energy for later use. Why do solar systems need a battery? Since the sun is shining only for a part of the day, we use it to store the excess energy and later on release it when we need it. The way a battery stores energy can vary from chemical power storage to gravitational and even thermal potential. The commonality to all of them is that they allow us the flexibility to generate electricity when the power is available and to use it when it is needed. Such flexibility allows us to rely on sustainable power-generating systems and to have a greener future.
Are batteries for solar systems sustainable?
Most commonly the batteries we use to store solar energy are lithium-ion based. lithium is a mineral that we excavate out of the ground in big mines mainly in South America and Australia. This process is energy demanding and has a carbon footprint. Currently, the technology used in those batteries is a lithium-ion gel which is pretty hard to recycle. We only recycle about 5% of the batteries that are out of use. Although this process is not yet carbon neutral we increasingly adopt sustainable sources of energy to make it cleaner. recent developments in this field such as the use of solid-state lithium batteries should allow us to make this industry circular and sustainable. The main reason that lithium wasn’t recycled until now is the higher cost of recycling compared to mining. With increasing metals costs in recent years, more lithium manufacturers started developing their recycling capabilities.
What is the price of solar energy storage?
The price of energy storage is usually metered in a price per watt-hour of storage. The price of a kW/hour of energy capacity is at around 1500$, a domestic scale system should contain about 1.5 kW/hours per user.
Meaning the solar energy storage capacity needed for a household of 4 people is 6 kW/hour. The price for such installation will be around 10k$ including labor costs and an inverter. This lower bound is referring to a system that could only supply for nighttime without electricity and assumes that the sun is shining strong enough to charge your batteries for the entire day. If you aim to have a few days off of self-sufficiency you can take into account the fact the average household of 4 will consume about 25kW/hours a day. The general range for a domestic scale solar power storage would be between 10 to 40 thousand dollars.
Some of the new options in this field such as tesla’s power wall aim to increase this price even lower.
It has great financial reasoning to build your system in stages. Start with the initial investment in solar panels installation costs and inverter, and after a few years add the batteries without much of a change to your system.
Is power storage for home solar systems Cost-effective?
The short answer is that it’s complicated. Solar battery system prices range from 10-40k$ to the average household solar system. With this price, it will take you on average a decade to cover the cost. While for a solar system including just panels and an inverter you could cover your investment a few years earlier than that. That figure gets even worst in the context of the fact that the average battery efficiency is about 70%. In the upcoming years, we expect a rise in the energetical efficiency of power storage as well as a lower price per watt of storage. Combining those effects the financial reasoning ( ROI for such investment) will probably become more appealing.
Nonetheless, there are a few benefits to having your independent energy storage which is hard to attach a price tag too. Some of the benefits are resistance to changing power costs or grid technical issues, and self-sufficiency, as well as the increase in property value after such an investment. Since the value of those benefits is subjective we will discuss each one of them further.
Batteries for home solar systems have a lot of benefits
Resilience against inflating power costs – with rising electricity prices, the financial reasoning for relying on your self-sourced electricity is becoming clearer. After the initial investment, you will know exactly how much you are going to spend on electricity for the next two decades. A nice recommendation is to take your annual electricity cost and multiple it by the years of the durability of the system you choose, this should be your budget. as electricity prices keep on rising it will be more obvious to you how much you saved by taking this decision.
Self-sufficiency – could benefit you in a few ways. First, there is great satisfaction in knowing you are independent of the grid and can provide your energetical needs in any case. Moreover, the idea of taking a consumer choice that benefits the planet is fulfilling. Besides that in a scenario where there is a disruption in the power supply or future taxation on power consumption, you will not be harmed by those consequences.
Increasing the property value – the green investment in solar energy systems will serve also as a financial investment in your property. There are various estimations as to how much your property value will increase by the installation, ranging from a flat 4% to even 20$ for each dollar you could save in utility bills. Nonetheless, they all agree that a home solar system will raise your property value.
Batteries for home solar systems are not perfect as well
Batteries efficiency – unfortunately, lithium batteries for home solar installations can store only up to 70% of the generated energy. This means that you will lose a lot of energy in the process. We estimate this figure to raise in the next few years with recent developments and new options for how you could store the power output of your system. Therefore at this point, you might consider waiting a little more and starting with the installation of solar panels while carefully planning stage two which will be the energy storage system.
Installation costs – As we explained before the ability to store your harvested power comes with a heavy price tag. similar to the last disadvantage we can expect the market will eliminate this drawback in the next few years,
With new companies entering this niche the future of solar systems sure looks promising. By the time the cost will be lower it is still not yet achievable for every household. If you are just getting into solar, you might consider taking the previous tip of planning a two-stage installation. Besides the previous benefits of it, you could also be more precise when pricing the storage capacity you need, which as you probably understand by now, could make a huge price difference.
Batteries for home solar systems are surely an interesting topic. We hope you got your head a little more clear about the benefits and disadvantages of them as well as what they practically mean and the environmental costs of them. There is no one solution to suit us all, and this one is another amazing feature that is well-suited for some and less for others. The power storage for domestic solar systems is another method in which we can build together a more sustainable future.