Ambient heat is renewable too, and can be used at 600% efficiency

Posted on October 12, 2011 by

0


The following excellent article is by Matt Wright, Executive Director of Beyond Zero Emissions. The article first appeared at the Climate Spectator, where it was accompanied by an interesting discussion in the comments section about energy efficiency – which is also worth a read.

Why I have six air conditioners

Matthew Wright

A year ago I retired my old, dirty and inefficient gas wall heater, when I had it confirmed that it was using a significant amount of energy heating up outside rather than just inside my house like I would have expected.

Australians are generally unaware about the renewable heat resources available to domestic households, as a clean, safe and efficient competitor to dirty fossil gas.

That’s why I bought six air conditioners. Air conditioners have a bad name and a bad rap and it’s completely unearned and unfair. Air conditioners are wonderful technology, like a laptop computer, smartphone or radiology machine. Air conditioners should rightly be called heat pumps, because they pump heat from one location to another. In doing so they concentrate that heat. They can pump heat out of our room making it feel cooler. Or than can pump heat into your room making it warmer.

There is nothing to feel guilty about here.  What you should be feeling guilty about is if you don’t have a reverse cycle air conditioners, and you’re heating with gas or electric resistive (bar radiators, oil filled heaters, electric fan heaters etc).

A funny game has been getting played confusing the public. Advocates for lower retail domestic energy bills have tried to make people feel guilty about air conditioning and comfort (who intentionally buys an uncomfortable bed to lie in?)

Heat pumps are reverse cycle air-conditioners and Japan and the United Kingdom have given huge financial incentives to move their households to heat pumps for heating as part of a national energy savings program, so why should Australia not do the same?

Our domestic energy needs can now be met fully with renewable electricity through installing renewable heat pumps for air and water heating and induction cooktops. In addition, the change would cut hundreds of dollars off everyone’s annual energy bills. No more monthly gas network service fees in addition to less actual energy bought off energy companies and more generated locally in your own “virtual power station” at home.

After I discovered I could stay comfortable with renewable energy and a clean conscience, I splurged on air conditioners, six to be exact; however I was really investing in reverse cycle systems mostly for heating because to put it into perspective, heating is so much more important when it comes to reducing carbon emissions than cooling.

In the winter, the energy used by Victorian households heating with gas is about 70 times that of cooling in summer, (80PJ vs 1.1PJ). However by using reverse cycle air conditioners we can cut down total gas and electricity energy use for heating and cooling by more than 80 per cent.

This was shown on my last bill which showed that I used 90 per cent less energy for heating thanks to refrigeration, which is an 1850s invention that inspired today’s inverter reverse cycle air conditioners which I’m now taking advantage of, and which are so efficient at heating and cooling.

I also have a 5kW solar system, which will produce slightly less energy than my reverse cycle air conditioner and heat pump boosted solar hot water system will save annually. Basically put I am getting more renewable energy from my air conditioner than from my solar system. My three renewable systems go so nicely together giving me a 100 per cent renewable powered household,  which is made up basically of Renewable direct solar electricity, renewable solar thermal, and renewable ambient heat  that relies on very small amounts of renewable inputs from the grid (large scale wind and solar).

As for my six air conditioners, many of my friends have questioned me on whether the system, if running on a small amount of ‘brown coal’, is cleaner than gas? Yes it is.

Gas is so inefficient that by the time it gets to my house, 15 per cent is lost in processing energy, distribution fugitives and another 30 per cent up the chimney as lost heat.

If I was running on brown coal, with my heat pumps however, 600 per cent equivalent of the energy generated at the coal plant is put into heating the room on an annual average basis The payback time of this highly efficient energy efficiency technology is usually less than a year.

Unfortunately many reverse cycle units sold in Australia, are still performing poorly. The Australian test condition is seven degrees C and the best units run at 500 per cent efficiency at this temperature (and even higher efficiency at higher temperatures which are the norm in most cities most of the time).

Current Australian Government Minimum Energy Performance Standards (MEPs) allow poor performing units to be sold. Units that are just effectively 300 per cent efficient, but without policing in reality many units, mostly from China perform much more poorly, some barely achieve 200 per cent effective efficiency and are preventing the market from expanding. The lack of stringent regulation and policing of reverse cycle air conditioners is costing Australians, both young and old, on their monthly energy bills.

It is also disappointing to consider that under the Renewable Energy Certificate Scheme, I would have been given upfront a $10,000 incentive if reverse cycle air conditioners were properly recognised the same way that Solar Hot Water is recognised; almost completely offsetting my $12,000 installation cost. Why the Office of Renewable Energy Regulator/federal government has failed to recognise air source heat pumps for heating while correspondingly recognising Hot Water air source heat pumps is a perplexing question. Why is there a bias against reverse cycle air conditioners as a renewable generator?

If we were to shift now to renewable ambient heat from bar radiators, oil filled electric heaters, resistive blower heaters and gas; Australians would save between 70-80 per cent of annual domestic, commercial and industrial space heating requirements. This should include a mandatory or certificate base scheme to update and replace old outdated box style and other pre-inverter or old inverter air conditioners. The key to this efficiency drive is the inverter units that perform with extremely good efficiency as they are able to vary their compressor speed to efficiently suit the cooling / heating requirements of any moment in time.

Renewable technology will only become available in the domestic sector, if there is overwhelming public support, and in a country of increasing hot and cold extremities, comfort is of fundamental importance and needs to be delivered efficiently and reliably. Heat pumps live up to the task and can do the bulk of the heavy lifting in keeping Australian’s warm in winter and cool in summer.

A buildings efficiency program can be thought of as a “virtual power station”, with Solar Photovoltaic, Heat pump boosted Solar Hot Water, Reverse Cycle Air conditioning, bulk and silver Insulation, air sealing, induction cooktops, and efficient LED lighting making up components of the power station. We must also include audits and upgrading of existing poor performing air conditioning units at no or little cost to consumers as part of a comprehensive plan to build the one big community wide “virtual power station.”

We need to take a cool headed approach and evaluate all the options and Renewable Heat using heat pumps is the biggest onsite renewable source available to all Australians especially those in high rise units who may miss out on the opportunity to install solar hot water or rooftop solar photovoltaic panels.

The Zero Carbon Australia Buildings plan will be released in February 2012 and explains how Australian’s buildings can use less energy as one big virtual power station, saving consumers, saving carbon emissions and committing Australia to the global shift to a 21st century efficient renewable powered clean tech economy.