E-News Issue #44
Microwave ovens are an energy efficient method of cooking many food items compared with using an electric hotplate, stove or oven. However, they still use a lot of electricity on a Renewable Energy system. We normally recommend using LP gas for most of your cooking needs unless you have surplus power from your system.
The power used by a microwave oven is also a bit confusing for the novice to appreciate. When you look at microwave ovens in the shop, most will have a big glossy label advertising the output power. This label will typically read between 500 – 1000 watts. Many people will assume that this is the power that the appliance consumes. This is not the case! The actual power drawn from the power point is typically 40% greater. This higher figure will usually be written on the compliance/specification label on the back or bottom of the oven.
The situation is worse again when you run the microwave off an inverter. They have a fairly poor power factor and are not an efficient or easy load for an inverter to run.
We recently checked a typical microwave oven. The glossy label advertised the output power to be 800W. The compliance specification label read 1150W. When run off a Selectronic SA22 Sine Wave inverter, the current draw on the DC side was 70A @ 24V or 1680W – more than double the advertised 'output power'.
Depending on the size of your system and the current state of charge of your batteries, this may still be an acceptable load when you consider that a microwave oven is often only on for 3 – 5 minutes.
Renewable Energy Certificates
Please note that these certificates are only applicable to our Australian friends. If you are overseas this last article is not likely to be of any interest to you.
Now you can have a Renewable Power System and get a yearly payment for allowing someone else to take the credit for having your Renewable Power System. A recent Act of Parliament requires all electricity generating companies to source at least 2% of their electricity (over and above their Green Power Generation) from renewable sources by 2010. To allow the trading of renewable energy to take place, the government has allowed for the creation of Renewable Energy Certificates (RECs). You must first apply to obtain the RECs before they are available to sell to others.
Where to Apply for RECs
You need to apply to the Office of the Renewable Energy Regulator - phone (02) 6274 2192 to obtain the application form in order for the Renewable Energy Regulator to allocate the appropriate RECs.
Requirements and Registration RECs are available for solar, wind and hydro power systems as well as for solar hot water systems. RECs are only issued for electricity created after 1st April 2001, or after the date you registered, whichever is the latter. If your solar power system produced electricity before 1997, your baseline is the average amount of electricity produced in 1994, 1995 and 1996 measured from exact solar output.
You can claim RECs only for electricity produced above this amount after 1st April 2001. In order to apply for your RECs, you must either estimate the deemed output according to a simple formula provided in the application form, or use exact measurements. There is a $20 fee for registration of a certificate owner, and a $20 fee for accreditation of your solar, wind or hydro power system as a renewable energy generator.
The accreditation fee is only required if you aren't estimating the deemed output but are using exact measurements. If you are assigning your RECs to an electricity retailer, the accreditation fee is $50. If you are opting for measured generation, the accuracy of the meters will need to be verified and then you will need to provide an Energy Generation Return to the Renewable Energy Regulator every year, detailing how much electricity you made from your renewable energy source. Solar, wind and hydro power systems can be bundled into the same RECs.
You can create RECs annually or you can aggregate them for 5 year periods. This means that you could be earning 5 years worth of RECs at once.
Solar Hot Water:
New Solar Hot Water Systems are also eligible for RECs. However, the RECs are bundled, that is, you receive all the RECs for the hot water system in one go instead of annually. Hot water systems are also given a deemed output depending on where you live and the type and size of hot water system you have.
Negotiating to Sell RECs:
Once you have obtained the RECs you can negotiate with wholesale electricity purchasers and electricity retailers or any other interested parties to sell to them. In so doing you lose your right to claim that you derive renewable power from whatever sources you sold the RECs for and the purchaser of those RECs can then claim that resource as a renewable energy source of their own.
They won't actually own the power system, nor will they own the power derived from it, all that they can do with it is to claim greenhouse gas reduction points, a bit like conscience money.
To the owner of the renewable power sources, RECs can be used to subsidise their own power system or as a means of obtaining a small income from a renewable energy system.
What are RECs worth?
RECs will have a value based on the number of megawatt hours of generation they represent. As with any other tradeable commodity, the value will depend on how much demand there is for RECs compared to how many RECs are in the market.
The power utilities are required to generate a certain amount of their electricity from renewable sources by law. If they don't meet the required target they will be fined $40 for each megawatt hour of renewable energy that they fall short of this target.
This means that RECs will never exceed $40 in value. 1 REC = 1 megawatthour of generation.
We estimate that 1 REC will be worth between $25 and $35. A 600W solar array anywhere in Australia would qualify for 1 REC.
Hydro and wind have been given a default resource availability.
The default value for wind is 2,000 hours per year and for hydro it is 4,000 hours per year. Individuals wishing to claim more than these levels must provide proof of their claims based on site specific auditing.
Based on the default value, the Rainbow Micro Hydro would be deemed to be worth 1.2 MWh of generating capacity.
Cheers from Dave and all the RPC crew.
Dave Lambert (Director)
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