With the global shift towards sustainable energy solutions, many homeowners are exploring alternative energy sources. One question that often arises is: Can a solar generator power a house? As someone who has delved deep into the world of renewable energy, I can confidently say the answer is a resounding “yes.” But, as with most things, the devil is in the details. Let’s unpack this
What type of solar generators are there?
Solar generators generator and store energy that can be used when the sun isn’t shining. They’re especially handy during nighttime, cloudy days, or in poor weather conditions. It’s like having a backup power source that kicks in when your primary source (the sun) is unavailable.
Solar generators made up of a few different pieces of kit that plug in together: solar panels, a battery storage system, an inverter and an MPPT controller (solar controller).
There are a couple of different types of solar generators. So let’s get clear on them first.
- Rooftop solar generator – describes solar panels fixed to your roof with a large battery – like a Tesla Powerwall – hanging from the wall in your garage or somewhere outside your home.
- Portable solar generator – describes solar panels on a fold out frame that can be packed into a suitcase sized bag and a lightweight, energy-dense battery you can carry or move around on wheels.
Can a Solar Generator Power a House? The Answer
The Straightforward Answer
Yes, a solar generator can power a house. Both a rooftop solar generator and some large or expandible portable solar generators can power a whole house. However, the extent to which it can do so depends on several factors.
- Household Energy Use: Every household is unique, just like its energy needs. A family home will have different energy needs from .
- Geographical Location: Living in sunny California or Queensland means more sun and, therefore, more energy generation compared to, say, often-cloudy Seattle or chilly Tasmania.
- Size of the Solar Generator: Just like how a bigger water tank can store more water, a larger solar generator can store more energy. We’re talking about size in kilowatt hours.
Understanding Your Energy Needs
Evaluating Daily Consumption
Before diving into the solar sizing, it’s crucial to understand your energy consumption. Look at your electricity bills, understand your peak usage times, and determine your daily energy needs. It’s like knowing how much water you need daily before buying a water tank.
Tailoring Solar Solutions
Every home is unique, and so are its energy needs. A one-size-fits-all approach doesn’t work here. It’s essential to tailor your solar solutions based on your specific requirements.
So lets demonstrate how to tailor a solar generator solution to power your home.
What Size Solar Generator Do You Need?
Understanding the size of the solar generator you need is crucial to your hip pocket. It’ll save you money.
It’s akin to knowing the size of a water tank for your home based on your daily water consumption. Let’s delve into a tailored solar generator solution, using examples from two different locations: sunny Queensland and chilly Tasmania.
What to Consider
Before we jump into the numbers, lets point to the factors that influence the size of the solar generator you need:
- Daily Energy Use: How much energy does your household consume in a day?
- Sunlight Hours: How many hours of effective sunlight does your location receive? This is where our different geographic locations come in.
- Battery Needs: Why do you want the battery? Do you need to store power for blackouts, nighttime use or something more?
Next, lets see how these factors combine to determine the size of your solar generator.
A Typical Home in Queensland
Daily Energy Use: 16.81 kWh
For a home in Queensland that is still connected to the power grid, we use a daily energy use of 16.81 kWh.
For this house, we want the solar to run everything in the day and the battery to run everything at nighttime, when the sun isn’t shining.
We also know that around 70% of the household’s energy us is typically at night. So the battery has to be charged enough when the sun goes down, to provide 11kWh of power.
Using these numbers, we can determine our solar panel size and battery size.
Battery Size: To cover the nighttime energy use, a battery size of around 16kWh is ideal. When you account for energy losses when the battery operates, you can reliably expect 11.8kWh of power out of this size battery.
That takes into account a Round Trip efficiency of 90% and a Depth of Discharge of 80%. Typical performance for a lithium ion battery.
16kWh x 0.9 (RTE) x 0.8 (DoD) = 11.5kWh
This is roughly equivalent to 1.2 Tesla Powerwalls.
Solar Output: Given the sunny climate of Queensland, they use a solar output factor of 4.2 kWh per kilowatt of solar panels.
💡’Solar output factor’ is what everyone uses in Australia to estimate solar ouput.
💡You can also use ‘peak sunlight hours’ for your location to get solar output, if you don’t know the solar output factor. Here’s how to use peak sun hours to calculate solar output. And a map of daily sunshine hours for Australia. They have a similar map of solar radiation for the US.
To generate the required 16.81 kWh, a solar system size of around 4kW would be sufficient, which translates to about 12 solar panels of 350 watts each.
4kW x 4.2kWh/kW = 16.8kWh
A Typical Home in Tasmania
Daily Energy Use: 32kWh
For a Tasmanian home daily energy consumption is much higher at 32.26 kWh. This is because it’s butt cold in Tasmania. I know, I live here. Our heating load is high all year round.
Battery Size: Considering that 70% of this energy is used at night, we need a battery storage of approximately 22kWh for nighttime.
To cover the nighttime energy demand of 22kWh a battery size of around 31kWh would be ideal. This equates to about 2.3 Tesla Powerwalls.
31kWh x 0.9 x 0.8 = 22kWh
Solar Output: Tasmania, being less sunny than Queensland, has an average solar output of 3.5 kWh. To generate the required 32kWh, a solar system size of around 9kW would be necessary, translating to about 26 solar panels of 350 watts each.
9kW x 3.5kWh/kW = 31.4kWh
Final Thoughts on Sizing
These numbers are based on typical homes in these regions. Individual needs vary based on specific household consumption patterns, the efficiency of appliances, and other factors.
Here’s an article that takes you thorugh how to size a solar generator for your home, step by step.
You can also reduce the size of your solar generator by becoming more energy efficient, using energy during the daytime and converting to other types of power sources – like the wood we use for heating in Tasmania, instead of power hungry electrical heat pumps.
The Realities of Using A Solar Generators to power your Home
Cost Implications
Investing in a solar generator requires an initial financial outlay. It’s like paying for your power upfront. So consider this if you have plans to move home.
Because it is an upfront cost, you’re not exposed to power bill increases that you are if you’re getting all of your power from the grid. So solar is a big power bill killer. Let’s look at the potential for savings.
Potential for Savings
Solar power is cheaper than grid power in most places. In Australia solar costs roughly 10 cents/kWh. Grid power is around 25 cents/kWh and rising. So you always save money installing just solar panels.
Over time, as you harness more solar energy, the return on investment becomes evident. It’s like planting a tree; the initial effort is high, but the shade and fruits it offers over the years are rewarding. A solar system will typically pay itself off in around 4 to 6 years, depending on where you live.
Your geographical location plays a big role in the efficiency of your solar panels. For instance, homes in sunnier states like Arizona or Florida or Queensland in Australia are likely to get faster returns on their solar system than those in less sunny areas. Like Tasmania or Seattle.
After your solar system pays itself off in power bill savings, all of your solar power is free.
But batteries are not the same.
Batteries are still an expensive investment. And because of this, the cost per watt of power from a solar generator (solar + battery) is often still more expensive than you pay from the power grid.
They’re not yet at ‘grid parity‘. Or the same price as power from the grid.
We’ve done some calculations to show cost per kilowatt hour of a portable solar generator that we own. It’s closer to 50 cents/kWh for the solar battery over it’s lifetime. Because of the portable battery costs.
Keep in mind that rooftop solar generator would in many cases be cheaper than a portable one. Due to economies of scale.
The Future of Home Solar Generators
Where is a solar generator ‘worth it’?
Sometimes the power from a solar generator is inherently more valuable than grid power. Here’s some examples:
- When you live at the fringe of the power grid and have to pay tens of thousands to run a power line to your home. It can be cheaper to get a solar generator.
- When you live in a mobile home. Like in RVs, campervans, tiny homes or caravans. Solar generators might be your only option.
- In extended blackouts or frequent power outages. A solar generator will save your sanity and everything in your fridge.
- When there is no power grid anywhere near your location and you have to provide your own power (off grid).
Most people expect to pay more for electricity at their fingertips, in these situations. And this is where solar generators are growing in popularity.
Declining Costs
The good news for solar enthusiasts is that battery costs are on a downward trajectory. This means that as time goes on, solar generators will become even more affordable.
Adding to that, the cost of batteries is coming down all the time.
Maximizing Benefits
Start with solar PV, and as costs decline, gradually integrate batteries. It’s like building a house brick by brick, ensuring each layer is strong before adding the next.
Both solar and batteries are modular technology. So make your installs cater for this. That you have the right brand and type of panels, battery and inverter so you can add more power later.
Use solar to power your home in an incremental way. Add a small battery when costs come down. Add more batteries to that unit when the costs decline further. Slowly build up the capacity of your solar generator to meet your home energy needs.
Complementary Solutions
Backup Generators
Imagine this: It’s been raining for days, and your solar generator is running low on energy. You’re on edge. Your home may just run out power.
This is where backup generators come in.
They ensure you have power even during extended periods of bad weather. It’s like having an umbrella in your bag, just in case it rains. If you’re wondering how it works check out our article ‘If you have solar do you need a generator? How to get reliable power in 5 minutes‘.
Off grid solar generators often include emergency backup generators. Diesel generators are popular. But you can also get bundled solutions.
A home backup kit, that includes solar panels, a portable battery, back up batter units and an emergency back up gas or petrol generator.
Ecoflow makes one of these bundles with their dual fuel gas and solar generator. You get the convenience and quiet of solar batteries, with the reliability of gas to back it up in rainy weather.
In a Nutshell
Solar generators are a viable solution for powering homes. While the initial investment might seem steep, the long-term benefits, both environmental and financial, are substantial. As someone who has witnessed the solar revolution unfold, I can attest to the transformative power of the sun. Harnessing this power efficiently and effectively can lead to a brighter, more sustainable future for all.
