How dependable is renewable energy?

Let’s answer about dependable renewable energy from the perspective of a home on the national grid or one operating in isolation. The question is about what renewable energy source is dependable. The response may be considered from a view of which is most reliable (a measure of consistency). Another way of looking at this is to consider the long-term abundance or availability of the energy source.

Grid-scale dependable

On the scale of a national grid, you can generate any amount of electricity by whatever means is most efficient.  The generator can be in one or more places and the distribution infrastructure will convey electricity to the nationally distributed customer base. Hydropower, solar farms, wind-energy farms and such renewable resources can be used for grid-scale domestic power demand.

Make renewable energy dependable as renewables can be

Hydropower is the largest source of dependable renewable power. Hydroelectric plants get built in the path of massive rivers and are hugely expensive. Once built, they will last for well over a century providing power at a very low marginal cost. This is a renewable energy source that is dependable in the long term. Hydropower plants with adequate permanent water supply are not intermittent generators like solar and wind.

Hydroelectric power plants are effective base-load suppliers of power. They need huge water supplies and ahead of the construction they often have active opposition. Because of the large areas of natural land, they inundate when their reservoirs fill, building a dam needs careful environmental assessment and approvals. The proposers might relocate and re-establish flora and fauna before they start planning works. Hydroelectric plants present an attractive opportunity to generate massive renewable energy without any GHG output.

Less dependable renewables

The regular focus for renewables has been on wind turbines and solar PV arrays in farm-scale operations. These are commercial operations but solar is a regular renewable in residential applications. The primary source of energy for wind and solar is from the Sun. The solar panels operate to produce electricity while there is available sunlight. On this planet, most places have solar access in a yearly pattern that is predictable and reliable. Solar PV panels have no moving parts and can operate for 25 years or more. The appending electronics to complete the solar PV systems often have shorter effective lives. Inverters that convert the panel’s DC output into usable AC supply may last 10 to 15 years.

We may question which of the renewable energy sources are most dependable on a domestic scale. The answer depends on whether the property connects to the grid or is autonomous. If the property operates independently of the grid the renewable energy source to be used is unlikely to be hydro or geothermal power. The property could use a hybrid combination of wind and/or solar PV, with a generator and/or batteries. We might note that both solar and wind energy solutions are dependent on their technologies being available at the required scale.

Adding batteries

These renewables both operate with a level of intermittency, which needs you to consider what to do when no power is available. If we intend to keep the supply solutions limited to renewables, a rechargeable bank of batteries needs to be installed. A correctly sized bank of batteries will ensure a dependable consistent electricity supply. In a residential setting, a solar PV set up more easily blends with the urban landscape. With inverters, the solar direct current electric power plants can supply AC matching the existing power infrastructure and domestic appliances.

Solar energy systems with long warranties can be designed to be dependable. They must be installed competently with correct wiring to other electronic components like inverters, and charge controllers to batteries. Some systems may add a generator and switching to be seamlessly and safely integrated into the existing electrical system. Solar energy has good accessibility because it can be easily sourced and there are abundant skilled people to install them. Wind turbine generators could similarly provide the household with an alternative or supplementary electrical supply augmented with batteries. Wind turbines on residential homes may attract a degree of resistance from the neighbours and the local approving authority.