Why is my electricity bill so high over summer?
We are all worried about energy bills and you may have had a larger summer electricity bill than typical. This may help explain why.
The main reasons your bill has increased if your pattern of use has not changed significantly, are likely to be :
Continuing record heat prompting much higher air-conditioning electricity consumption. This is due to the combination of increased running times with a significant drop in air conditioner efficiency at high temperature:-
- There is more heat to remove in such conditions,
- The air-conditioner is running longer hours…many people do not realise how much,
- It is much more difficult for the air conditioner to ‘push” heat into higher temperature outside air. This lowers its efficiency.
- Due to the drop in efficiency, the air conditioner could be using 3-8 times more electricity to produce the same level of cooling as required when the weather is milder. Please see below for a more detailed explanation.
- Different solar panel energy production and different Feed-In-Tariffs.
- The use of monthly estimated meter readings between actual quarterly meter readings if you have an older style meter that requires a physical visit to read it. Estimates are largely based on the previous month’s usage. When a cool month follows a hot month in summer, or, if you are away from the house during the month, the cool month’s usage can often be over-estimated by the Regulatory specified process used by the Meter Reading companies. Any estimates will be ‘trued-up’ at the actual meter read which occurs approximately every three months.
- The use of estimated readings is eliminated using Smart Meters that are read daily via telecommunications.
Pooled Energy is progressively installing smart meters for its customers (subject to their agreement), to eliminate such estimates.
Air-conditioning.Many people do not understand why air conditioning costs vary. The recent hot summers have resulted in additional costs for almost all users. An air conditioner is a heat pump, which works by transferring heat from one place to another. When an air conditioner is used for cooling, it transfers heat from the inside of your house to the outside air. When on “reverse cycle” it transfers heat from the outside air into your home to heat it.
The energy efficiency of an air conditioner is a key measure of an air conditioner’s performance and is called the Coefficient of Performance (COP). A COP of 6 means that the heat pump will transfer 6 units of heat for 1 unit of electricity at a particular set of house internal temperatures and outside air temperatures. The COP varies with the difference between the inside and outside temperatures with a range of 10:1. The key to the COP or efficiency is the difference between the internal air and the external air temperatures.
In typical air conditioners, the useful operating temperature difference is about 20 degrees between internal and external air temperatures. If you are cooling the house and the outside air is only 5 degrees hotter than the inside air, you may typically achieve a COP of up to 6 from your air conditioner. If the temperature difference between the inside of the house and the outside air exceeds 20 degrees, the COP can fall to between 1 and 2, and to below 1 in extreme cases. This means, that, depending on the type of air conditioner, you will be using up to 3-7 times as much electricity to achieve the same amount of cooling when the outside air was only 5 degrees hotter.
When the outside air differential is high, you also typically have the dual issue of also having much more than the normal heat load to get rid of. Overall, you may be using as much as 10 times the ‘typical’ amount of electricity to produce the same perceptive result. The effect on power consumption is exponential and not linear and you can consume significantly more electricity and run up large electricity bills on hot days. This situation is exacerbated if the humidity is high.
Most electricity companies record only your total house electricity consumption, which is based on the reading from the Government authorised meter at your house. Pooled Energy also records the energy use of the pool and its equipment every two minutes as the Pooled Energy equipment contains an additional electricity meter for each major piece of controlled equipment in the pool (and optionally in the house). This is how we know that the pool’s energy use is greatly reduced and you are saving from the substantial reduction in electricity consumption. We can provide detailed data from the additional metering if you require it.
The NSW Government subsidised solar feed in Tariff for eligible customers ended on 31 December 2016 – a date legislated by the NSW Government when they first set up the scheme. With the removal of the subsidy, most households are exporting power to the grid at a price below that which they are buying power from the grid. In this case, it makes sense for the power produced from the solar panels to be consumed in the household before more-expensive power is purchased from the grid. Please see the Solar Optimisation software we offer for no additional charge for PV panel (and pool solar heater) owners. This enables you to lower both your energy usage and your charges. We believe it provides a significantly better solution than batteries, which are still very expensive to install.
Estimate verses Actual Meter Reading.
Your certified meter is read on an approximately 3 monthly basis as required by government regulations. This means your monthly invoices between meter reads are based on estimates provided by the government authorised meter provider. Any over or under charges are corrected when the data is collected from an actual meter read. The estimate is done by a methodology approved by the Australian Energy Regulator based on your recent consumption history. With the hotter and high energy consumption months in the immediate past, some estimated bills may be estimated on the high side. Any over charges are corrected following the actual meter read.
An alternate to the cycle of estimate and actual meter reads is the installation of a smart meter. Smart meters send daily via a communications network your half hourly consumption to the meter provider who then forwards this data to Pooled Energy for billing purposes. This enables all bills to be issued based on your actual consumption. Please contact us at firstname.lastname@example.org for further information on smart meters. Pooled Energy customers are currently able to opt for a Smart meter at no additional cost.
If you have any concerns regarding your bill or are interested in other aspects of this post, please do not hesitate to contact us at email@example.com