Constraints of Solar Power for Self Sufficient Living

By janiner, 19 June, 2024
Opinion
Battery for Solar Power

With all the talk about the non-urban area being developed for self-sustained living or an eco-village, I keep wondering how this can happen whilst still retaining the bushland setting that we all love.

There are two obvious choices for power- connect to the grid or solar. 

Connection to the Grid

To connect to the grid, you need wires. These are either above ground on posts or underground. Whatever method is chosen, the bush tracks would need to be widened and lots of trees and bushes would need to be removed.

Solar

We have two solar systems with battery storage, one on our house and one on our caravan. 

Our house has clear solar access with panels facing east and west as there is no suitable north facing roof. There are no trees or hills blocking solar access and our power bills are currently in credit. In summer, if it is sunny, we can run our house on solar, providing we don’t use the air conditioner or other power intensive devices all day. We also have enough to send quite a bit to the grid. In a recent planned power outage, our solar system worked quite well. The day was partially sunny, it was still summer, and we had enough battery storage with solar top up during the day to outlast the outage.

In winter it is a different story. Our solar still generates excess power, but it is a lot less than in summer. It is insufficient to run the air conditioner for heating for long periods, electric stoves and other high power usage devices. Obviously, we could build a bigger system, but we are constrained by the roof size and shape, the neighbours’ trees and the amount we wish to pay for the battery storage system.

A town on the south coast has recently put in its own solar battery storage system and connected the house top solar systems to the battery. This town is already connected to the national grid with its own power and wires to support the battery system. The small-scale battery system just overcomes the problem of local outages and reduces everyone’s power bills. It is an idea worth considering for our village area.

Our caravan also has a solar system. It works well provided we park our caravan where we are in the sun, and we orient the caravan to maximise our solar access. If the batteries are full and it is cloudy or shady, we can last two days without moving, using the power for lights, pumps, charging our phones and so on. Devices with high power requirements such as hair dryers, toasters and electrical heating/cooling systems quickly deplete the power. In summer it is a catch 22. If we are not travelling, we need the sun to charge the batteries, so we need to be in the sun, which heats up the caravan and then we need to use the air conditioner. We can partially overcome the problem by using portable solar panels, which we move to stay in the sun. 

Again, in winter it is a different story. We need to constantly monitor the system to ensure that we have enough power and when we run low, out comes the generator. Generators are noisy and a last resort.

Both our solar systems run well but there are constraints. You need solar access, so no trees or south facing hills. Preferably the panels should face north. House systems need micro converters on each panel if some of them get shaded when others are in the sun. You need sunny weather. Two days of cloud is enough to run down most systems. You also need good battery storage.

However, I fail to see how a solar system can provide enough reliable power for self-sufficient living in a bushland setting. The only way would be to remove most trees to ensure sufficient solar access. Even then, a bout of cloudy weather, especially in winter, will result in no available power. Even thermal efficient houses that don’t need heating in winter rely on the sun for passive heating. Yes, it is possible to be off grid, but there are compromises such as the removal of trees for solar access, smoke from wood burning fires, expensive housing costs to ensure thermal efficiency and the necessity of alternative energy sources such as gas, diesel generators and unreliable wind generators.

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