It seems everyone these days has solar panels. 3 million Australian homes, to be precise. But how many of us really rely on our solar when we need power most? If you’re set on a solar powered future for your family, then there’s one question that comes up more than any other: If you have solar do you need a generator? The answer is not as straightforward as it may seem. This article nails everything you need to know in 5 minutes, drawing from my 10 years experience running solar projects and programs in Queensland.. So buckle up and join me as we delve into what it really takes to power your home yourself.

If you have solar do you need a generator? 60 second summary

No, you don’t need a generator if you have solar AND you are connected to the power grid. Even in a power outage, a solar system can be set up to provide uninterrupted power supply. Otherwise known as UPS, an affordable solar battery can give you seamless backup power for a few hours if the grid goes down.

Yes, you do need a generator if you have solar when you’re NOT connected to the power grid. This is because:

• solar is sun and weather reliant and sometimes you wont have enough of either
• solar + batteries are expensive if you need to oversize them for a few days of backup power off the grid – fuel generators can provide cheaper alternatives than batteries
• fuel generators can also provide a higher power output, to run energy hungry appliances for longer
• if you want to run your whole house from solar 24/7, it’s ideal to have all 3: solar + battery + backup generator. 3 power sources can take you comfortably off the grid.

Shedding Light on Power: Solar vs. Traditional Generators

Before we can address the question at hand, it’s crucial to understand what solar power and generators entail.

Solar power is the conversion of energy from sunlight into electricity. This process is facilitated by photovoltaic cells found in solar panels. It’s a clean, renewable, and sustainable form of energy that reduces reliance on fossil fuels. However, its effectiveness is subject to weather conditions and daylight availability. No sun, no power.

On the flip side, generators convert mechanical or chemical energy into electrical energy. They are typically powered by fuels like gasoline, diesel, or propane (LPG). Generators are reliable and can provide power regardless of weather conditions or time of day. However, they are non-renewable, produce emissions, take a lot of maintenance, and are pretty noisy.

You can read about the pros and cons of solar vs a traditional generator in this comparison post.

If you have solar do you need a generator?

The answer is ‘sometimes’. Let me explain.

Solar power now plays a pivotal role in providing household power in Australia. We’re also relying more than even on solar to power our recreational activities. Like camping, caravan-ing or RV-ing.

If solar panels absorb sunlight, convert it into electricity, to use in our appliances or store in batteries for later use. It follows then that the performance of solar panels is affected by weather conditions and the time of day (sunlight). For instance, on a cloudy day or during the night, the energy production of solar panels drops.

Solar panels on the power grid

Now, if your home is connected to the power grid, you have instant access to a giant backup generator for your solar panels. When your solar is not producing enough electricity for you, the grid will fill the gaps. And when your solar is producing too much power, the excess can also be sold into the grid.

This covers the vast majority of solar powered households in Australia. And there’s 3 million of us.

It’s important to understand that if your solar panels are grid connected and there is a power outage, your solar panels will turn off. This is a safety feature called ‘islanding’. It’s there to stop the power workers from getting electrocuted when they come to fix the grid.

BUT! You can arrange to safely have your solar system stay on in a power outage. And with battery, it can provide you with backup power for a few hours.

This is called uninterrupted power supply or UPS. You need a battery that has UPS capability. And you’ll pay extra to have your solar battery wired this way.

We recently had a 4 day power outage in the middle of winter in Tasmania without backup power. I don’t recommend it.

Off grid solar panels

But what if your home and your solar panels are not grid connected, or you don’t want to be grid connected?

How do you meet all of your energy needs – even for those power guzzling creature comforts – all of the time, without the grid?

Or, what if you’re hitting the road, going ‘full nomad’ in your RV or caravan? Or looking to embrace the ethos of tiny house living?

This is where a backup power source, like a generator, can come in handy.

It’s also where the answer to our question ‘If you have solar do you need a generator’ is a definitive ‘YES!’.

Here’s what you need to know…

The role of generators

We’ve already acknowledged that solar power is an excellent source of energy, but that it’s not always consistent due to its reliance on weather and daylight.

This is where a generator steps in.

Like the power grid, a generator can serve as a reliable backup power source, filling in the gaps when solar power falls short. It can provide power during the night, on cloudy days, during power outages, or when high-demand appliances need to be used.

A generator is like a safety net, ensuring that you’re never left in the dark. And that’s an important point. Because it helps us understand when we need a generator with solar panels, and when we don’t.

You see, generators are best used as a source of backup power for solar when you don’t also have access to the power grid.

The role of batteries

Batteries are starting to displace generators as a backup power source for solar. Solar batteries are even replacing the power grid in some situations.

Batteries store electricity generated by the solar panels, allowing for power usage when the sun isn’t shining or in poor weather.

Lithium batteries, in particular, are a popular choice due to their efficiency and ability to provide power for a longer period. However, they are a big investment. The decision to use batteries instead of a generator should be based on your power needs, budget, local weather conditions, and how often you might need backup power.

Check out this article ‘Solar or Generator (What to know before you buy)’ if you need help deciding which is best for you.

As battery storage gets cheaper, the role batteries play in our home power will grow.

If you want to know how solar + batteries + a generator work together (and when you need all 3), keep reading down below.

The benefits of using solar and a generator for off grid living

Living off-grid presents a unique set of challenges, particularly when it comes to power supply. In such situations, having both a solar system and a generator isn’t just a luxury; it’s a necessity. This combination ensures consistent and reliable power, a critical factor for maintaining a comfortable and functional off-grid lifestyle.

Solar power is an excellent resource for off-grid living. It provides a renewable, sustainable, and cost-effective power source that aligns perfectly with the ethos of off grid life.

But reliable and continuous power off the grid requires solar with a backup generator for when the solar power is insufficient. The back up generator runs at night, or on a string of cloudy days.

Generators are particularly useful for powering high-energy appliances that solar power might struggle to handle, such as heating systems, air conditioning units, and large kitchen appliances.

A dual power system like this offers a level of energy security that is crucial for off-grid living. It ensures that you’re never left without power, and can live as comfortably as though you were on the grid, even in the most remote locations.

Solar system with battery AND backup generator

Most off grid home electricity systems these days use a powerful combination of 3 different energy sources to achieve continuous and reliable power: solar + battery + backup generator.

But why would you still need a generator if you have solar panels and a battery?

Well, the solar is your primary power supply. It runs in tandem with the battery to supply all of your power needs, 24/7. But! If you’re running your whole house with a solar battery, it can become an expensive proposition. There are a few reasons why this is:

• if you’re not able to rely on the power grid, it’s critical to size your solar and battery to cover your highest energy demand. It’s usually seasonal. In some locations you need the most energy in winter, when days are shortest and sunlight in short supply. This means you have to upsize your solar battery system to cater for these conditions (and its cost), or use less power.
• extended periods of poor weather can result in not much solar power to fill your battery. Off grid homes cater for 2 to 3 days of backup power to cover this. Depending on where you live, it could be longer. This also increases the size of the battery you need, and your costs.
• Batteries are not always a cost effective solution. Prices are coming down, but they’re not there yet. So using batteries to cater for your highest energy demand or provide an extra 2 to 3 days backup storage is not always cost efficient.

Hence, many off grid homes go with solar + batteries as well as a backup fuel generator for when the weather really hits the skids. The generator allows you to more carefully size your more expensive solar battery system, and avoid oversizing it to cater for those rare times you might not have enough sunshine.

If you want to know about running whole house solar generators, check out this article Is a whole house solar generator what you really need?

Can you use a generator if you have solar panels?

Solar panels and fuel generators are not mutually exclusive; in fact, you can use them harmoniously to power your whole home 24/7, 365 days a year.

Here’s how it works: during the day, when the sun is shining, solar panels generate electricity, reducing the need for generator use and saving fuel. At night or during bad weather, when solar power production is low, you can switch to your generator. This interplay can create a balanced energy system that optimizes the benefits of both power sources.

But there are some things you need to know first, to get the integration bit right. And to decide whether you use a fuel generator or battery when sunlight isn’t available.

1. Power Requirements

Understanding your power needs is crucial. You need to know how much energy you use and what your aim is, to determine the right size generator. This includes considering both your regular power usage and peak power demands. Is your generator just for outages? Or do you need it for high energy guzzling appliances too?

If you want to know more about how to size your kit, check out ‘How many solar batteries are needed to power a house (5 tips to save you money)’

2. Compatible electrical parameters

Not all generators and solar systems are compatible. You can’t just plug any old thing into your solar panels or inverter.

Instead, you need to ensure that the generator you buy can work in tandem with your solar system. This often involves checking the inverter type and the generator’s output specifications. It also involves making sure other electrical parameters – like voltage, frequency and current – are compatible between your generator, solar panels and inverter.

This is where you may need some advice from an expert. Or you can buy an already bundled solar + generator kit, like the Ecoflow Smart Generator, which is a plug and play gas and solar generator.

3. Fuel type

Generators can run on various fuels, including gasoline, diesel, propane, or natural gas. The choice of fuel impacts the generator’s efficiency, cost, and environmental impact. It’s important to choose a fuel type that suits your needs and preferences.

Solar or Generator? What to know before you buy compares the costs and benefits of solar vs diesel vs gas generators. It’s a great article if you want the differences summarized in 60 seconds.

4. Noise level and convenience

Generators can be noisy, which can be a problem in residential areas or quiet campgrounds. Some generators are designed to operate more quietly than others, so consider the noise level when choosing a generator to go with your solar panels and inverter.

Fuel based generators also need to be located outside, away from your living area. Not just because of noise, but because of the gases they emit. Think about whether running cables outside is going to be convenient long term.

5. Maintenance

Generators require regular maintenance to ensure they run efficiently and have a long lifespan. This includes tasks like changing the oil, replacing filters, changing spark plugs, and general cleaning. Consider the maintenance requirements of different fuel generators, and whether you’re willing and able to meet them.

We considered a diesel backup generator for our rural property at one point. One key reason I decided to to go ahead was the servicing and maintenance requirements. They were just way over my head or interest level. Especially whether there were other plug and play backup power options out there.

6. Automatic Transfer Switch

An automatic transfer switch (ATS) automatically switches power sources from your solar system to your generator when the solar power is insufficient. This can provide a seamless power supply without manual intervention. In some cases you don’t even notice the switch over. You do pay extra for the convenience and they have to be installed by an electrician.

7. Cost

Generators vary in price, depending on their size, brand, and features. Consider your budget and the cost-effectiveness of the generator in the long term, including fuel and maintenance costs.

It’s not just about your upfront outlay. The lifecycle costs of running a fuel generator (fuel costs, servicing, maintenance) should not be underestimated.

8. Environmental Impact

While solar power is a green energy source, generators can produce emissions, depending on the fuel type. If environmental impact is a concern for you, consider a fuel generator that runs on cleaner fuels like natural gas or propane, or look for models with lower emission levels.

Considerations for RV Users

Generators can be controversial with campers due to their noise level and emissions in shared spaces like campgrounds and parks. It’s unsurprising then that portable power stations with super quiet solar panels and battery storage are becoming commonplace in RVs and caravans these days.

Systems like the ones produced by Ecoflow or Bluetti make it possible to take power with you to any campsite, no matter how remote. And run it without much noise.

For RV or caravan users, the need for a generator alongside solar batteries can depend on you camping style.

f you prefer full hookups or always have electrical power at your campsite you might not need a backup generator. The same if your electricity needs on the road are modest.

However, if you enjoy dry camping or boondocking, where electrical hookups are not available, a generator to backup your solar battery can be really beneficial. A generator can also provide power for air conditioning, heating, and other high-energy appliances that portable solar battery might not be able to handle for extended periods.

Conclusion

Whether you need a generator if you have solar depends on whether you have access to the power grid or not. Having a solar battery and backup generator provides the most powerful, reliable and flexible solution. However, it’s essential to consider factors like cost, noise, and your power needs before making a decision. And if you’re mystified at the prospect of buying solar panels, a battery and a generator that work together, don’t worry. You can always get at bundled unit like the Ecoflow Smart Generator. It’ll save you the time and stress of trying to DIY your own kit!