Webdiary - Founded and Inspired by Margo Kingston

Sometimes it's Free 

My last monthly power bill (November 2010)  was $9.  Sometimes its free.  For a family of five running medical equipment , electric stock fencing, pond pumps 24 hours a day, and our domestic water supply from our own tanks pumped up by an electric pump to house, gardens and livestock, that's quite an achievement! In answer to the assumption that a hybrid solar/wind system can only contribute a little to urban power consumption and not meet rural needs, I would obviously disagree.

Opa Chris's Story

We have our own power-generating infrastructure thanks to my late father-in-law who provided an enormous financial boost.  He knew at first-hand what the collapse of civilization looked like. In 1945 while on the run from a Russian PoW camp, he made his way across the frozen plains of Poland, eating putty from the ruins of bombed out buildings and eventually his own boots to still hunger pangs. Haunted that something like that could happen again, he did not want his Granddaughters to face similar experiences through dependance.  He also felt that human life was costly for this planet, and as he was dying and could have no further direct input to this world, he wished to offset his genetic legacy with a positive gift to a future that could be made sustainable.

Our System

Our system is a grid interractive system, just over two years old and consists of a 1 KW wind turbine feeding a battery back-up and then the grid (surplus power is paid for by the utility provider), and 18 solar panels which export through two inverters to the power grid. The PV (photovoltaic) panels also power back-up batteries which can run the household for up to three days if power goes down from the grid (for example, from fire or tempest - a fairly frequent event over time in this region).  The roof needed a reinforced rack to hold the panels.  The pitch needs to be better than 13 degrees,18 is optimum, and to be north facing (in this hemisphere anyway).

The turbine has three blades and a braking system for when the wind is too strong.  It is mounted on a 65 foot tower, with four huge gyre wires anchoring it to concrete blocks!  It needs 100 meters, and a tractor, to belay the lines, to lie down for maintenance!  This is not an optimum situation, as the wind blows all night. Yet we cannot access that power.  We must draw from the grid and pay accordingly:  it is stored in batteries and is not used unless the grid is disconnected.  Some form of power storage is necessary in all off-grid systems, as power supply is often seasonal, and no sun or wind may provide power for many days, or even weeks, at certain times of the year.

Stand alone or Grid interactive - Pros and Cons:

This is the problem with legislation and meeting the requirements of the grid.  I would suggest anyone thinking of switching to PV/wind systems have confidence in the technology, and go OFF GRID.  If I had my time over again, that is what I would do.   Even though there would be no subsidy, the cost would be less up-front anyway. The process was a 50% (or less) Government subsidy,  which had a lot of attendant conditions.  As many countries are considering meeting their emission requirements by creating schemes and subsidies to encourage more people to put solar arrays in place, it is an issue that needs consideration.  The station was not allowed to exceed 5 kilowatts.  If it had, I would never have needed to IMPORT power from the grid.  

The tariffs that are paid (by the State government and the energy supplier) for my exported power offset some of the cost, and enable the government and Companies to "buy" my power in a scheme to offset their carbon debt.  Again, the issue remains of compliance.  A smaller and cheaper system can be installed with one interactive inverter, 5 KW or higher, for a fraction of the cost of the four inverters that have to break up the flow of power and allocate it to the grid, battery store and domestic use pre-export.  This is blatantly a waste of power, and profoundly inefficient.  If subsidies are sought, and more government infrastructure for these new intiatiatives is demanded by people, then compliance issues and accountability will be an ongoing consideration.  (Note from Pushing Green:  If you would like to know more about Karen's expenses, send us a note.  Numbers haven't been included here because of the complexities of subsidies, government regulations and utilities laws which are relevant in Australia and not necessarily in North America.) 

The Issue of Service Provider Accountability:

However, relying on PV/wind system with only your own battery back-up, the new industry of domestic provision of power needs to meet more stringent warranty, post sale support, and technical support.  It is a profoundly alientating experience to have a non-local provider whose responsibility effectively ends within a year of installation.  Any problems with the system are as unfixable as the national grid itself, for the individual.  To myself, who tries to DIY everything from her plumbing to her building, this has been a frustrating and intimidating experience.  And of course as the system was a gift, I cannot afford to fix any faults that may develop.

Meeting Needs of Disabled and Elderly People:

Obviously, to meet the needs of a greener future, aternative energy systems MUST perform as well as their coal-powered alternatives.  My system was tailor-made for the needs of a disabled person.  To be an effective alternative to mainstream power provision, it is necessary that PV/wind systems perform as reliably as the grid. In general, for us, this has proved to be the case.  When the power goes out from the grid, we get nothing but a flicker of lights and then the system switches to battery back-up. The ventilator doesn't falter and the computers don't crash!  As you can imagine, with sick, elderly or life support dependant people, this is a profound reassurance!  This back-up is necessary when a system is off-grid, as seasonal variation means sometimes no power is generated for many days, a downside to stand alone, off-grid systems.

Problems:

There have been a few "teething problems" with our system. The wind turbine seized and had to be lowered to the ground.  I have a tractor of my own, but there was no one locally to get to perform the maintenance, and I found that the warranty period for such an expensive piece of equipment did not cover repair over one year. This is pathetic and unsatisfactory, and would not be considered appropriate in any other industry, I'm sure!  The inverters were not set up right, and the power was not getting allocated correctly.  This was reducing the system's efficiency.  And finally..and this is a BIG one.  CHECK your domestic appliance efficiency! The system was generating power well enough,and yet my power bills were still quite high.  No fault could be found.  Sometimes replacing old appliances, or repairing them, can be the most "green" thing you can do!  My fridge compressor was sub-standard, and had to be repaired: suddenly, I was getting a CREDIT on my accounts!  The power system was fine, but my fridge was not.

I hope this gives people a realistic idea of the processes,technology and possible issues with an alternative energy system.  I am more than happy to discuss any issues people have regards the PV/wind hybrid power generation systems. 

Glossary:

PV or photovoltaic. Solar panels that obtain power from the sun .

Solar array: number and configuration of PV panels

Wind turbine: blades spin and a generator supplies power. Measured in Kilowatts (KW) in Australia.

Inverter: converts DC power (from battery or solar cell) to AC ( domestic power)

Battery storage: the deep cycle cells that store the power the PV/wind system generates.

The Grid: the power provided by the power supplier for the region. A grid interactive system both feeds power to the grid, and enables power to be drawn from the grid when none is being generated.