In this special Energy Matters article, we talk to Neal Stewart â€“ co-founder of Edge Electrons, creator of the EdgeIQ voltage regulator â€“ about a little-known fact about our electricity grid: that we are paying for more electricity than we actually needâ€¦
While debate about the high cost of electricity is now a national obsession, the idea that Australian consumers are being force-fed unnecessary electricity is not so widely known.
The cause of the problem is fluctuations in grid voltage, and voltage affects how much energy appliances use. This is a result of Australiaâ€™s grid becoming more unpredictable as old power stations close down. In March 2018 the Australian Energy Market Commission, key energy advisor to the Commonwealth Government, released a report on the problem.
It found Australia has a reliable amount of power supply but keeping that supply stable is becoming harder. â€śManaging the power system â€“ keeping things like frequency and voltage within technical limits â€“ is becoming more challenging,â€ť the commission warned.
The problem of changing voltages in our powerlines has even been the focus of an ABC TV 7:30 Report program.
The problem is that the electricity grid was designed to have massive coal-fired power stations monopolising power distribution to homes and industry. This made it easy to control the voltage across the power lines.
The massive increase in wind farms and rooftop solar in Australia over the last decade has changed this situation. The grid is now faced with power feeding in from many different sources, which makes it hard to maintain a steady voltage in the power lines. The distribution network managers have not kept pace with changing conditions, and have not introduced the technology that could solve these issues.
The result is that an Australian company is now warning about high grid voltages and offering a solution. Edge Electrons says customers are in fact paying for electricity they donâ€™t need. High voltage is also wearing out appliances before their time. Edge Electronsâ€™ device, the EdgeIQ, offers a solution to these problems.
The EdgeIQ is a household voltage regulation device that does two things:
Wangaratta-born Neal Stewart is a scientist, inventor and co-founder and CTO of Edge Electrons. After an international career in the power electronics industry, Stewart looked at the emerging problem of Australiaâ€™s grid stability. He says the companyâ€™s name reflects its mission: to bring power electronics regulators to the edge of the electricity grid to protect the consumer.
Stewart told Energy Matters that data shows customers could save 8-10 per cent on their electricity bills if home voltage remained at 220-230 volts.
â€śFor every 1% reduction in voltage thereâ€™s 1% reduction in kilowatt hours,â€ť he says. â€śBut it goes the other way too, and this is where the consumer gets hurt and doesnâ€™t know it.
â€śIf thereâ€™s a 5% increase in the grid voltage, consumers are paying an extra 5% in kilowatt hour usage because the appliances are using more energy. The appliances run at 230 volts, then anything above that they start to eat up more power.â€ť
In Australia, electricity distributors must deliver 230 volts plus 10% or minus 6%. As a result, the range is 216 â€“ 254 volts. This is not ideal for efficient appliance operation.
â€śYou can have continuous high voltage and then you have very high surges,â€ť Stewart says.
â€śI was in Melbourne recently and there was an electrical storm. We have circuits in the EdgeIQ to protect the house from that. We can also see voltage surges of 265, 275 volts â€“ we have the data.â€ť
Stewartâ€™s data collected from EdgeIQ regulators installed in homes gives a first look at whatâ€™s really happening to the power supply.
â€śNo one has done this,â€ť he says. â€śWeâ€™re putting EdgeIQ units on the house so weâ€™re reporting these voltages and we have high resolution data.â€ť
The idea for the EdgeIQ came after Stewart researched the impact of renewable energy like wind and solar power on the grid. He saw the emerging problem of voltage stability because of renewables like rooftop solar feeding into it.
â€śThe EdgeIQ is a voltage regulation device for houses,â€ť he said. â€śItâ€™s really useful for homes with solar PV systems. It uses power electronics and software in a device attached to the house that stabilises the grid voltage. We literally separate the house from the grid, and thereâ€™s no other technology out there that does that.
â€śWhen we put the EdgeIQ on the house, we can process the power so that we arenâ€™t concerned about the fluctuations on the input. The consumer is fully protected, because high voltages damage appliances.â€ť
When it comes to solar, the most vulnerable part of the energy system is the inverter. Stewart cites Queensland government research into solar inverters.
With high voltage, the invertersâ€™ relays switched on and off too often as they tried to protect the device, which effectively wore them out. â€śOnce again the consumers are out of pocket because of high voltages damaging their solar inverters,â€ť Stewart says.
Inverters use a self-protective tactic known as over-voltage lockout, or OVLO. This disconnects the inverter from the grid when it encounters high voltages. Because inverters can only deliver 216 to 254 volts, if the voltage approaches the 254 volt limit, they disconnect from the grid.
Proper regulation of the voltage to the inverter prevents this. But it also lets the inverter feed more power into the grid, benefiting households on a solar feed-in tariff.
â€śIf you put the solar inverter on the output of an EdgeIQ, the solar inverter only sees 220 volts. If it tries to increase that voltage and the house is not using the power, the additional energy is now boosted back to the grid to maintain that 220 volts.
â€śSo in addition to protecting the house and optimising the energy usage and lengthening the life time of appliances, the EdgeIQ also optimises solar export to the grid.â€ť
The EdgeIQ also reduces home energy consumption without households having to change their electricity behaviour. The energy saving happens quietly in the background by the EdgeIQ.
Stewart believes the future will be one where small power networks produce energy for local use. This model, known as distributed energy generation, is where electricity is fed into the grid from a number of sources. These include rooftop solar panels and wind turbines.
These microgrids will replace the current distribution model, where electricity can travel hundreds of kilometres from the power station to the home.
â€śWeâ€™re going to see microgrids being funded, probably publicly, driven by market demand. They will have large batteries servicing a number of houses in the microgrid,â€ť Stewart says.
â€śThis is total disruption in a classical legacy industry, and itâ€™s chaotic. The whole system will break up into high level networks controlling local generated energy on microgrids.â€ť
What will come out this disruption is a new kind of electricity network, based on microgrids. In this new model, consumers will have more control over the amount and quality of the electricity they are using.