A few years ago, solar power was fairly expensive and inefficient; and it only attracted the most dedicated environmentalists. But now, with reasonably priced and highly efficient solar panels, solar power is much more accessible and practical.
So, can a home run solely on solar power? Yes, a home can run solely on solar power if you install sufficient batteries or have a net metering system in place.
Energy self-sufficiency is very liberating. Even though it is possible, it may or may not be the best option for you. Let’s see how
Evaluating your situation to check if you can live on solar power alone
1. Determine your energy usage
The first step is to analyze your power requirements. You can do that by examining your past electricity bills. However, you have to keep in mind that your electricity requirements vary by months and seasons.
You will need more electricity during very cold and very hot months. Also, check the power rating on your appliances. Some appliances like electric kettles can use 3kw of power!
2. Check Net Metering Rules
Net metering is a mechanism in which you send your surplus power generated by solar panels to the electric grid. The power companies will give you credits for that
This system allows you to transmit excess power during peak production hours and receive electricity during the night or cloudy days
In most places its compulsory for the power companies to provide net metering, However, its best to inquire about them beforehand
3. Factor In Battery Costs
Batteries that go along with solar power systems can be fairly expensive. A 13.5-kilowatt-hour Tesla Powerwall, for example, has an installed cost of $11,000.
If you don’t want to connect to the grid or live at a remote location, the battery is the only option for you. However, there are many cheaper setups out there if your power requirements are lower.
4. Calculate Annual Solar Power Output
Not all places have the same luck when it comes to solar power. Places like Yuma get over 240 days of sunshine, while Tulsa gets less than 130 days of sunlight.
You would have to look at annual weather patterns in your city to get an idea about how much power you can realistically get.
5. Access Your Budget
Once you know your power requirements, you can determine the costs of the solar panels, batteries, etc. Then, check if you are willing to spend the amount required to fulfill 100% of your power needs.
6. Inquire about Government Incentives
Various governments provide grants and tax credits to make solar power more accessible to the people. In the US, for example, there is a generous 26% Federal ITC (tax credit) for solar power systems(2021)
7. Availability of space
Solar panels require significant space for installation. It would be best if you placed them in a bright spot away from disturbances.
To give you an idea, a small 330W solar panel takes about 19.5 sq. ft. of space, while a 5 Kw panel requires 312 sq. ft. of area. Mostly these are placed on the roof; if that’s not an option, the ground is the next best thing.
If you don’t have the required space, it won’t be easy to satisfy your power needs solely with solar panels.
How many solar panels do you need
To be completely dependent on solar power, you need to fulfill your 100% electricity needs. An average household in the united states uses 877 kWh per month. That’s 29.23 KWh per day. One 310 watts solar panel getting 4 hours of the sun produce 1.24 KWh in a day. So, to fulfill your daily requirements, you will need around 24 solar panels.
This is a fairly rough estimate, but it will give you a good idea about the number of solar panels you need
Also, One 310 Watts panel cost between $210 to $450
How many peak sun hours do you need?
Peak sun hours are defined as hours during which the average sunlight reaches 1000 watts/meter²
Knowing the peak sun hours is crucial in determining the actual energy output you will get from your setup.
To have a well-performing solar power system, you need at least 4 peak sun hours. The number of peak sun hours depends on your location. Arizona, for example, gets 6.5 hours, Washington gets 4.38 hours of peak sun.
Grid vs. batteries
During peak hours, your solar panels will generate more energy than required. If you plan to be reliant on solar power, you can’t let it go to waste. You have two options; either use it to charge the batteries or send it back to the grid.
If you charge batteries with it, you can use the stored power during the night when solar panels do not produce electricity or during the cloudy days when output is very low.
However, batteries will add a considerable expense.
The option to send it to the main grid will get you power credits. Usually, for every unit you send to the grid, you get one unit credit. When the solar panels are not producing power, you can use these credits to buy the electricity you need. In some places, you can also get paid for the surplus power.
No additional expense
Considerable expense ($4000 to $11,000)
Does not increase the payback time
Increases the payback time (For average home its 15 years with battery and 8 years without it)
Still dependent on grid
Independent of grid
When should you choose a battery?
The net metering arrangement is not the same everywhere. There are three main types of net metering.
- Full Retail – In full retail, you are paid the full amount that the electricity company charges other people for electricity.
- Avoided Cost – This is the amount saved by not providing you electricity. This is fairly low.
- Time of use – In this model, electricity companies charge more during peak times and less during the off hours. This also applies to net metering. They pay you more during peak hours and less during off-hours. Unfortunately, the solar panels produce most electricity during the off hours.
So, if you are on full retail net metering, using a battery will not much sense as the cost of storing and sending to the grid is the same.
If you are on avoided cost or time of use model, you will better buy a battery. In these models, you will send the electricity back to the grid at very low prices and receive it at a higher cost when you need it. So, the financially sound decision is to store it.
Battery Net Metering
Battery Net metering is a new concept that is signed into California law. Under this law, utilities can also purchase energy stored in user’s batteries. So users can use or sell their stored electricity as long as it’s 100% solar-generated.
Most users who opt for solar power never look back. With highly reliable and durable options like Tesla solar, you can be sure that you will get your investment back. The latest technology has made it possible to live on solar power alone. However, most users will find it more convenient to have a hybrid system to have an uninterrupted power supply.