The industrial revolution started around 1750 with the invention of the steam engine. Humanity started to burn fossil fuels on an increasing scale, changing society and beginning the steep rise in atmospheric carbon dioxide levels, which now sit at around 420 parts per million, higher than in the past 3 million years. The IPCC ARC 6 report of 2021 emphasises the need to rapidly reduce the use of fossil fuels to minimise the risk of catastrophic climate change. This scientific assessment urges humanity to move to a new energy system, in order to maintain the planet’s delicate environmental balance.
What are our options?
The use of fossil fuels is very inefficient as well as polluting.
Electricity produced using coal or natural gas power plants wastes a huge amount of energy. Many coal plants are only 25-30% efficient and natural gas plants 40-45%. A fully electrifed home powered by renewables will need less than 40% of the energy of its fossil-fueled counterpart. The Australian economy can run on far less energy when we embrace the electrification of everything. This makes the investment in converting homes to fully electric a very sound investment for the nation and does away with household gas use.
When the fossil fuels are left sequestered in the ground as our science knowledge advises, there are two energy choices at this time; Renewable or Nuclear Energy.
Nuclear energy has major issues with the long term storage of radioactive waste and the disastrous consequences of the fallout from the facilities failures.. Promoters of nuclear energy play down the risks and dangers of this waste, but there is little evidence to support our societies capacity to maintain a dangerous waste dump over the 150,000 years of so that is required. The industry claims the latest versions are better and safer than earlier models. However, our society does not want to go down this path despite Australia having significant Uranium deposits. As well, all the financial indicators show Nuclear energy is not the lowest cost option.
Renewable energy describes a wide range of options: Solar, Wind, Wave, Bioenergy, Hydropower and Hydrogen. Of these, Solar and Wind are being adopted on large scales, green hydrogen has numerous large investment proposals for use in industrial and transport settings and Hydropower as Pumped Hydro Energy Storage is also being funded by the Australian Government (Snowy 2), Queensland Government and other privately funded projects e.g Kidston PHES.
Financial markets show that Solar and Wind energy are the lowest cost sources of electricity. Lazards are independent financial advisors who publish this data as shown below. While this data is from the USA, it reflects world wide trends.
Australian electricity markets reflect this world wide value trend with large investments in Solar and Wind projects. The only fossil fuel generator proposal in Australia is funded by the Australian Government. The community has also adopted roof top solar as a form of low cost electricity.
Gympie Regional has one utility scale solar project under construction and another project proposed both at Lower Wonga, a Wind farm proposal within the Toolara -Tuan pine forests, a bioenergy program to capture and burn methane at the Gympie landfill site and 50% of dwellings have 61MW of solar panels installed. As a region we are doing quite well. Lightsource BP made a presentation at our meeting and advised they are now feeding 5MW into the grid.
Bioenergy, where crops are specifically grown to be harvested for energy, have caused disruptions to food markets and as a result have faded from the news. Using agricultural and forestry waste for energy may cause soil degradation as this organic matter is bot being incorporated into the soil and building organic carbon stocks. Bioenergy from waste also refers to methane produced when organic matter is decomposes in anerobic conditions, e.g. landfill and some sewerage systems. The methane is collected and either vented and burnt or used to supply energy to nearby users. There are small Bioenergy systems available for households, e.g. Home Biogas.
Bioenergy also is produced when waste is burnt and not sent to landfill. The energy may be fed into the grid or supply heat or energy to nearby users. However, burning waste is controversial. It discourages recycling and may emit toxic matter into the atmosphere.
Solar
Households and business are interested in roof top solar systems as it is the lowest cost electricity. It is produced on site and has no transmission costs added to it. This is the great advantage of a distributed energy generation system. Adding battery storage allows the storage of solar energy for use after the sun has set. The costs of solar and battery storage systems has fallen dramatically, making these systems competitive with grid sourced electricity.
Guidelines for purchasing solar PV systems and batteries can be found at these sites:
Clean Energy Council, Solar Citizens, Queensland Government.
The Clean Energy Council site also has lists of Accredited Installers and Retailers
A solar system consists of the following essential elements:
- Solar cells that are combined into a solar panel. This converts sunlight in to direct current (DC) electricity. These are linked in series or parallel to suit the system design. Overcast days will reduce the energy production by around 66%.
- Regulator that manages the energy flow from the solar panels to meet the capacity requirements of the rest of the system.
- Inverter to change the solar generated DC electricity into alternating current (AC) that is compatible with power from the grid. Some are also battery compatible, so the solar energy is left as DC and managed to charge your battery system.
- Batteries are used to store the solar electricity for use later in the day when there is demand for electricity or the sun is not shining. This reduces the grid in feed of electricity from the solar generator and increases the local household or business consumption of the solar energy. Batteries may also be used to help reduce overall grid power requirements.
Going off grid when already connected to the grid leads to a lower environmental benefit of the solar system as surplus energy generated cannot be used by others to reduce their fossil fuel consumption. Hybrid systems enable a grid connected solar system to become an isolated island with the energy available within the “island ” only. Your house is able to maintain its power use when the energy grid is down.
If not already connected to the grid, installing an off grid system maybe the lowest cost option for powering your household. You will probably be advised to install a back up generator. However, it is also feasible to over size the system so that even on a overcast day, you produce enough electricity to power the house and recharge the battery. This would require a smaller battery, than trying to cover the useage for say 2 to 3 days. However, you would need a solar system that is 3 times your normal use as overcast days reduce output by 66 %. The best option will depend on your circumstances and objectives.
GADSA can help answer your questions about these technologies and point you towards great sources of information. Contact us if you need help.