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The White Hat Guide to Electricity & The Environment

Electricity. Great stuff! You flick a switch and something happens. It replaced all sorts of dirty, smelly, inconvenient, inefficient, clumsy, polluting contraptions that were part of the home and the workplace in the 19th century.

But it has its problems – and opportunities. We thought we might us this newsletter to discuss some aspects of electricity.

Storage of Electricity

Many forms of electricity generation don’t produce the power when you need it. Solar power doesn’t generate at night, wind power doesn’t generate on still days and so on. Even hydro-electric which can often store its water in dams until needed has its problems. Unlike central to northern Europe and USA where much energy is used for heating, in Australia more power is used for cooling. Storing the water from winter when rivers are flowing at their peak in order to generate electricity for cooling in the summer months means that you are often watching your potential energy evaporate in front of your eyes as well as possibly starving the river system downstream of environmentally sustainable flows and farmers of irrigation water.

Then there are the generators in large power stations which can be slow to fire up and shut down (although technology has improved on this front in recent years) and they will operate at greatest efficiency when generating a fixed amount of electricity.

All of these things mean there is a need to store electricity for when it is needed. This is usually done by converting it into another form of energy which can then be re-converted when needed. On a small scale this may be done, as in the case of domestic solar panels, by converting it into chemical energy in batteries. On a larger scale the electrical energy might be stored as physical potential energy. For instance it could be used to pump water from a holding pond at the bottom of a hydro system back to the dam at the top ready for conversion to electricity when needed.

The trouble is that most of these storage methods are highly inefficient and you get back considerably less than you put in. There are also other problems. Most batteries contain polluting heavy metals and possibly acid and their responsible disposal can be costly. For instance we have been told that a number of the batteries currently used in Australia in conjunction with domestic solar panels require more energy for their manufacture and responsible disposal than they are capable of storing over their lifetime. This may have been a half-kown half-know but it reminds us of an excerpt from the Goon Show “What’s that machine Eccles?” “It’s a digging machine. It does the work of 10 men.” “That’s wonderful.” “Yes, it takes 20 men to operate it.”

Finding ways to efficiently store electrical power has great potential for reducing our overall carbon footprint.

Solar Energy

At the moment there are four main types of solar energy in use in Australia.

1. Photovoltaic – where light is converted into electricity. This is the principle used by most domestic solar panels. The energy conversion efficiency is very poor (but improving all the time) and there are the losses involved with storage of the electricity until needed, but – hey – that sunlight is free and would otherwise be wasted. They are not upgradable but need to be entirely replaced with the additional problem of responsible downcycling the metals from the older panels
2. Thermal – Converting sunlight into heat such as used by domestic solar hot water systems. Converting heat into heat is more efficient than the current domestically available methods of converting light into electricity, but there is still the issue of storage. Even a well-insulated domestic hot water system wastes energy at a disturbing rate if it is not used immediately. And if it produces more hot water than you need then that energy has been lost.
3. Concentrated Solar Power (CSP) as produced by arrays of reflectors concentrating heat onto a collector. This usually needs to be carried out at a commercial scale to make it viable but is then considerably more efficient than both the above methods. There may still, however, be considerable losses in storing and transporting that energy to where it is needed. Because if a photovoltaic converter is used, it constitutes one small component it can be easily upgraded.
4. And by far the biggest – natural solar input to the earth’s energy cycles. Cholesterol and nourishment is driven by solar power. Hydro power requires evaporation and subsequent rainfall driven by the sun.
   “O! how this spring of love resembleth
   The uncertain glory of an April day,
   Which now shows all the beauty of the sun,
   And by and by a cloud takes all away!”
   Sorry! What with all that sun and April and all I got a bit carried away.

We know that one Australian engineering company which is a major player on the world stage is seriously looking at setting up a major CSP project in Western Australia. No governments in Australia yet seem seriously interested in pursuing the renewable energy path in anything but a token fashion so they may need to approach another business such as a high profile Australian mining company in order to make it happen.

Why WA? It gets the last of the Australian sun each day at a time when the grid in the east is under its heaviest demand. Not only does north west WA produced consistent sun, it produces its ‘best quality’ energy-producing sun late in the afternoon meaning there are less storage losses for the local community peak early in the evening. The sun would be concentrated by an array of reflectors to heat specially selected oil. Unlike a domestic hot water system, industrially engineered hot oil storage on a commercial scale is capable of storing its energy with far less losses. Then, when needed, that heat can be converted into electricity via a steam turbine. To minimise transmission losses the scale would be well suited to a large industrial plant and associated residential community such as a large mining town. Where heat is needed, it can be extracted direct from the hot oil instead of being converted into electricity and then back into heat with all the losses involved. This process is known as cogeneration. Similarly, turbines are capable of producing the motion energy required by a number of mechanical processes required in industry without the losses of converting to electricity and back again.

We will watch with interest.

Electricity - action at a distance

One of the advantages of electricity is how effectively this energy can be transferred around the country. Instead of everybody having an inefficient small generator in their back yard you can set up an efficient giant generator with all sorts of economies of scale, pump the electricity into a grid and people can draw as much or as little as they want. Thus in the case of Victoria, the power plants in the Latrobe Valley pump electricity into the grid and someone in suburban home in Melbourne flicks a switch and the light goes on. Nothing has had to be put in cylinders or loaded onto a train or a truck and carted large distances. Once you have the grid in place you pump it in at one end and suck it out at the other end. Marvellous!

The major problem lays in the fact that transferring electricity over a distance nearly always involves major losses. It’s like putting $100 in the pipe at one end and watching $25 come out the other end. Australia is a large land mass with a relatively small population, and transferring electricity over large distances can be very wasteful. Much of the energy is lost as heat from high tension cables.

The closer the electricity can be generated to its point of use, the less the energy loss through transmission. For instance a suburban house might pump the excess electricity being generated by its solar cells during the day into the grid. That electricity might be used by a factory down the road thus reducing transmission losses substantially. Similarly that factory may be producing excess electricity at night which can then be used by the local homes. The whole process can be metered and monetary charges or incomes administered by the appropriate electric organisation.

However, while more local production and transmission of electricity can create efficiencies, the grid remains an inefficient way of storing energy, and even transmission over short distances involves energy losses.

Wasted Energy

Come with me to the southern part of the Australian mainland in winter. You will probably find a large power station in which coal or oil or gas is used to turn water into steam to power a turbine to generate electricity. Without an infinite supply of water, that steam needs to be cooled and turned back into water for reuse. This may involve large cooling ponds to get rid of the heat. The electricity is then pumped into the grid to go to the city but along the way loses much of its energy through heat. What is left of the electricity arrives in the city where a good portion of it is to be used to create - Heat!

But wait a minute, some say, what Australia wants much of the time is cooling so good riddance to all that heat. Well anyone who paid attention in secondary school science classes will soon tell you that heat can be used to create cold such as the burning of kerosene in that much loved icon of country Australia, Edward Hallstrom’s Icy Ball Refrigerator, through to the more recent techniques of the absorption chiller. When a process is used to efficiently produce electricity, heating and cooling it is known as trigeneration.

Domestic Appliances

Several generations ago it was understood that a domestic appliance tried to make optimal use of scarce energy. Thus a slow combustion stove was used not only for cooking but for central heating and as the hot water system. In more recent times with energy readily and cheaply available a typical Australian household may have a clothes dryer emitting heat, low voltage lighting in the ceiling emitting heat, a refrigerator emitting heat an air conditioner trying to cool it all down and then to cook tea you turn on the stove to create some more heat. Domestic appliances are designed with none of the efficiencies and co-generation capabilities of Mr Pratt’s factories.

Last year we went to a display by Fischer & Paykel of ‘The Kitchen of the Future’. The Kitchen of the Future consisted of numbers of stylishly designed appliances sitting next to each other making absolutely no use of the wasted energy of their neighbours. That is not meant as a criticism of F&P – it is a criticism of the household appliance industry as a whole. The average modern home has more energy wastage ‘built in’ than the average modern factory or office block. We at White Hat are no better than anyone else. Looking around the house it is hard to find any appliance that makes smart use of its wasted energy. Let us know if you come across some products you can recommend.

Rightsizing

We have discussed how large scale electrical grids can result in enormous wastage of energy. At the other end of the scale it can be just as wasteful of resources for each home to attempt to be self-contained for energy. At present it is not feasible for each individual home to use the efficiencies and cheap and easy upgradability of Concentrated Solar Power, Cogeneration, Trigeneration and so on. By all means those who generate their own power are doing great stuff while the rest of the community catches up. But the embedded energy and carbon footprint in all those inefficient photovoltaic solar panels, storage batteries, inverters and so on can be improved on. Finding the right size for a power system to have the lowest environmental impact is a challenge but most of the best systems at the moment seem to be coming in at around ‘neighbourhood size’. The good thing is that they are out there and working and with a business model that makes them capable of being retrofitted to an average Australian neighbourhood. One of our favourites takes advantage of economies of scale, limiting energy losses, cogeneration and trigeneration and cost savings for consumers. No legislation required. No look-at-me tokenism together with armbands and other merchandising. No carbon trading. No demonstrations saying “they” out to do something about it. Just some people who are Intelligent and Informed and are prepared to roll up their sleeves and do something. You can find details at the ABC website.