Load shifting can be a simple as scheduling the usage of optional, non-time sensitive appliances to run during the day rather than in the evening. Image by Photo Mix from Pixabay

Australian households are doing their bit to cut the nation’s carbon emissions by adopting solar rooftop panels but not all of them are saving on their energy bills.

There is no denying Australians have a love affair with solar. According to the Clean Energy Australia Report 2019, rooftop solar energy systems added a record-breaking 1.55 GW of new capacity to the electricity market last year, and one in five  Australians now have solar on their rooftops.

This trend shows no sign of slowing down. Six solar panels were installed every minute through the first two quarters of 2019. What’s more, the size of the solar systems being installed is growing, with the average size rising consistently from 1.34 kW in 2009 to 7.13 kW in 2018.

This incredible growth in solar adoption is clearly good news for Australia’s emissions reduction ambitions in the electricity sector. In its latest Quarterly Energy Dynamics Report, the Australian Energy Market Operator reports significant declines in both operational grid demand and emissions intensity, with the largest decrease (in emissions intensity) occurring at midday and credited to increased penetration of solar PV.

Source: AEMO Q2 Quarterly Dynamics Report: https://www.aemo.com.au/-/media/Files/Media_Centre/2019/QED-Q2-2019.pdf

These record-breaking numbers are starting to generate some interesting dynamics in the energy market. Already in South Australia, the “off-peak” time for the grid (the time of minimum demand) is shifting from the middle of the night when everyone is sleeping, to the middle of the day when solar PV is at its maximum.

In July, wholesale prices fell to zero or negative for the first time in all regions of the National Energy Market as cloudless skies and good breezes – combined with low demand – pushed the share of renewables to more than 43 per cent.

Source: Australian Energy Market Operator’s data page, screenshot @ 1:15 pm July 21st

Feed-in tariffs

So all good news then? Well, perhaps not for much longer for those who have invested their hard-earned savings in the rooftop PV systems that are driving this trend.

The problem is that most solar homes use the majority of their energy in the early morning and early evening when their solar system is not generating at its peak. They therefore rely on receiving feed-in tariffs (FiT) for the majority of the benefit from their systems.

This is a strategy that is already yielding poor returns. For example, in NSW since the solar bonus scheme ended in 2017, the FiT has dropped from 60c/kWh at the start of the scheme to an average of just 8c/kWh today. Meanwhile, average electricity prices have risen to around 35c/kWh.

This means that for every kWh of solar energy a household exports to the grid they have to buy it back again at more than three times the price in the evening – likely adding hundreds of dollars to their annual energy bill.

What’s more, with solar PV starting to drive wholesale energy prices down to zero in the middle of the day, it’s not hard to extrapolate the future trend. How much longer will the energy companies continue to pay consumers a FiT for energy that they could purchase from the wholesale market for free? Anyone relying on a continuation of the current FiT arrangements to realise a payback on their solar investment should urgently look at a plan B.

Load shifting

There is another way for solar households to ensure they are gaining the maximum possible benefits from the panels on their roof; they can consume as much of their solar energy as possible at the time it is generated.

In theory, it’s a simple strategy. Just schedule usage of optional, non-time sensitive appliances (dishwashers, pool pumps, white goods, water heaters, etc.) to run during the day rather than in the evening. Even most heating and cooling systems can be run on a timer, allowing homes to be pre-heated and pre-cooled on solar power before their occupants arrive home for the evening. No need for a “smart thermostat”; a simple dumb thermostat with a timer will do.

Source: Moreland Energy Foundation

Some solar homes using this strategy have been able to offset so much of their grid energy with solar power that their FiT credits exceed their charges for imported grid energy, resulting in a situation where their energy retailer pays them a refund every month!

However, many people find that maximising the benefits from “solar shifting” is tricky in practice. The challenge is that electricity is an invisible commodity so it can be hard to know how much energy different appliances need to run and at what time there is sufficient solar output to run them. Get the balance wrong and it may not be apparent until the next quarterly energy bill arrives, by which time hundreds of dollars in potential savings may have been lost.

So, before deciding on a battery as the next step on your solar journey, take a moment to consider whether that $10,000 investment is the wisest move. Solar shifting costs nothing to try and can deliver some amazing results.

Pete Neal, CEO and founder of Powerpal, is an energy data expert who has created a patented energy data acquisition technology to unlock the benefits of digital electricity meters.

Spinifex is an opinion column open to all our readers. We require 700+ words on issues related to sustainability especially in the built environment and in business. For a more detailed brief please send an email to editorial@thefifthestate.com.au

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  1. Great idea of the electronic devices to make up for lack of logic and commonsense of the public who are just so busy with their work, their mobile phone for “on tap” information and entertainment that they have no time to consider, and plan how they are going to survive the blast of the upcoming temperatures and everchanging climate.

    This situation of changing people’s perception of basic off peak load using solar power, is aptly known as occupant behavior, which no computer modelling can predict.

    Regarding battery backup. I would suggest the reader is not aware that the way the ABCB rate homes is for a fully airconditioned house with no radiant control of incoming solar radiation that naturally heats the building year round, and especially intense during summer periods.

    Thus, when there is no grid power the solar panel cannot provide power to operate air conditioning unless they have battery backup. So, do people have to get in a bath of cold water to survive?

    The promotion of these electronic devices demonstrate their immense benefits, however with no power the house has to be protected for the elements using the most appropriate materials and methods so at night the home will have a chance of being comfortable so when the power comes back on the assistance programs can beneficial.

    As the article says, at night time with no solar power, grid electricity is used, therefore during the day the home must be protected from the elements, with benefits if the power goes out, or at night, not running the airconditioner as long.

    In the quest for building energy efficiency the ABCB have conveniently opted for increasing the use of bulk fibrous insulation and there are “people” now acknowledging that houses have become “hot boxes”, I suppose that is more palatable, than “ovens,” thus requiring airconditioning.

    Yet, the ABCB have available numerous scientific reports, one of note the 2009 CSIRO- Gang nail report from within Australia for Australian conditions etc. proving with actual real house comparison testing, that reflective foils have benefits, winter, containing heat and summer cooler homes. Why hasn’t the ABCB mandated reflective foil radiant barriers to control solar radiation effects on residential buildings.

    Why is this relevant to the article, because the electronic devices being promoted which is a good and positive, has a bearing on how people live and survive in the homes, yet the first way to protect these people is to have the correctly insulated homes to reduce the strain on the electricity grid, and the renewables that people are “taking up” so they can live and survive in their homes.

    That the relevance of the how the Federal Government via the ABCB have no regard to correctly protecting how people live in their homes if the power goes down and they have no renewable power i.e. solar power with no battery backup.