Solar Electric - what's missing

The price of solar electric panels has finally (2013) fallen to $1.00US per nominal watt* and even lower.  This is the price which was often quoted as needed to make solar-electric financially viable.  The rate of solar panel uptake has increased but not as much as it should be.  What is missing??

*When a panel is facing directly into the noon day sun, it will produce a certain amount of power.  This is it's nominal wattage and it will be sold as such.  Of course, when the sun hits the panel at a shallower angle or there are clouds, the actual power produced will be less.

First off, let me say that this blog is predicated on the assumption that your government is committed to the premise that the uptake of small renewable generation feeding into the grid is good for the country.  You can take this with a grain or a spoon full of salt depending on which jurisdiction you live in. You will have all sorts of vested interests trying to scupper the uptake of small generation and some governments will be following along like puppy dogs.  However, for the sake of the argument, let's suspend belief and assume that your government has the best interest of the country and her citizens at heart.

What is missing is a defined relationship between the small generator and their power company that is fair to both and punitive to neither.  Short of a revolution in battery technology (and there may be one in the pipe line) it is not worth while for you to go off the grid.  When you generate an excess of power, it will be used by someone else and when you need a top up, the power company will provide it.  The Power company is essentially acting as your battery bank.  A diffuse power generating system has many benefits for the country.  It is almost anti-social and certainly expensive for you to go it alone.    Let's look at some of the considerations we should be concerned about.

Calculation Period
Say, in a hypothetical month, you are producing exactly the same amount of power that you use.  Your power bill for that month should be zero, correct?  Not so fast.  It depends on the calculation period.  Let's assume, further, that during half of the days of the month you produced excess power each day and half of the days you needed a top up.  Let's assume, further, that the power company charges you 20c/kWh* top up and gives you 10c/kWh for your excess**.  If the power company looks at the net top up or excess you used/needed over the month, your monthly bill will be zero.  If however, they do the calculation each day and tot up the result for each day, you will be paying quite a bit.  This argument extends to the seasons.  In summer you will produce more energy than you need; in winter less.  If you have sized your system to more or less meet your needs, if the calculation period is one month, you will be paying quite a bit for the lean months and getting a little for the good months.  If the calculation period is one year, it is of little interest how much you are charged for your net power use or how much you are paid for the excess power you produce.  For the good of the small generator, the longer the calculation period the better. 

*kWh - kilowatt hour - a measure of energy.  The Kilowatt is a measure of power.
** Nothing unfair about this.  It is one, amongst a number of ways to reflect the fact that the power company has to build and maintain the distribution network.

Single vs Double Metering
With single metering many of the problems fall away.  You turn the meter forward when you are using excess energy and turn it back when your generation exceeds your use.  This is often referred to as "net metering"

However with double metering there are a number of possibilities.   The German system is the most insidious.  In Germany you have one meter that measures every kWh you produce and one that measures every kWh you use.  This is not the excess you use above what you are generating or the excess you export above what you are using.  It is every kWh generated or used.  However, a double metering system can be set up so that you use your own generated power instead of the German system (you always thought that this is how it works, didn't you?).  The outgoing meter measures the excess you produce and the incoming meter,measures your top up.

Let's assume your power company is not using the German system so you only draw a top up or export your excess.  You are chugging along, working on your computer, pretty well producing the same amount of power that you are using.  You put the kettle on.  Suddenly you need to suck some power from the grid.  The incoming meter records this and you will be charged for the excess at the company rate.  The kettle finishes  heating your coffee water so you turn off the computer and go for a break.  You are now feeding power into the grid.   You get the reduced rate for the power you produce.  This minute by minute measurement is even worse than a daily calculation period. Your day is micro divided and you are charged for your instantaneous net use and paid for your instantaneous net production* (at the differential rate).  Of course the German system is even worse.  You don't even have the opportunity to use power you produce.

*I just struck me that there may be a fairly easy solution to this problem; the problem being that any instant you are producing excess power your output meter is recording it and any instance that you are using power, your input meter is recording it.  Simply install a modest amount of battery.  Say, for the sake of the argument, two lead acid truck batteries.  Then you just need the electronics to ensure that you access the power in these batteries before drawing from the grid and that your power goes first into these batteries before you export to the grid.  This would probably give you a couple of hours of buffering.

Now we come to taxation.  Do you remember that at the outset, I said we will pretend that your government recognizes the benefit of small diffuse generation and will face down all the vested interests (wouldn't that be nice for a change).  With the German system in which every kWh you produce and every kWh you use is measured or with the somewhat more benign system where your meters only measure your excess or your top up, you will pay income tax at your marginal rate for any revenue you receive and will pay GST (VAT) for every kWh you buy. If the government truly wants diffuse generation with all it's benefits, they should restrain themselves from taxing the system.  Taxation has two functions.  One is to collect revenue so that the government can do her good works.  The other is to direct the path of society.  It is hardly directing us to increase our uptake of solar technology by trying to milk the calf before it is even a cow.

Of course, the power company could say that they will simply subtract the excess power you use from the excess power you produce and charge or pay you, depending on whether your balance is positive or negative.  The government will then charge you GST if you buy some net electricity or charge you income tax if you earn some money from your excess.  If this is what they intend, why then bother with the expense of a second meter.  Far simpler to put in one meter which turns backwards when you are producing excess power.  If the power company and the government does try to peddle this line, watch out.  Suppose they say "we will have double metering but you will be charged or paid depending on the difference between these two amounts".  They are thinking ahead and hoping you are not.  At any time in the future they can decide to change the rules.  If you are double metered, they have you by the short and curlies.  But.......You have probably spotted the problem with single metering.

With single metering, the power company is essentially paying you the same for the power you produce and power you use  (except for any excess or deficit but that is another story).  The solution is simple.  There must be a line charge which reflects the fact that they must build and maintain the lines.  However, we come to another fish hook.  The power company will be tempted to  charge the simple user a larger price for their power and a very small line charge.  They don't need a line charge if they are getting a good price for the power they sell you.

For the small generator, however, they will charge a very small charge for electricity (and hence you will get very little for the power you produce) but you will pay a large line charge.  The solution is simple.  It must be legislated that the price per kWh and the line charge are the same for both types of customers.  The power company will work out the formula that optimizes their profits but will not be able to shaft either type of customer.  Incidentally, when there are few customers generating power, they will focus their attention on the simple user and this will be very good for the small generator.  This is great since it will greatly encourage the uptake of solar electricity at this early stage.  As more and more of us are generating our own power, the formula will change.

I have only touched on a couple of consideration to think about when structuring the relationship between the power company and the small generator/user.  Very little is the way it seems at first glance.  For Instance, in Germany, they give you three times the rate for the power you produce   than for the power you buy.  Are you ever suspicious when something seems too good to be true.  Most power users don't look any deeper.  The German system is far less  beneficial to the customer than it appears to be at first glance and increases the cost of power to all consumers.

Rebuilding Christchurch

                   Creating the Heritage for our Grand Children*

*While this blog talks about Christchurch, some thought should be given to implementing such measures in all areas of New Zealand.  All are prone to earthquakes.

My family and I have been very lucky.  We live about 50km north of Christchurch and while any earthquake above about a 4.5 rattles our house, only a few ornaments have been knocked off the shelves and the house hasn't taken any damage.  It would probably be a different story if a 6.3, like the recent one under Christchurch happened here.  One of our sons was driving in Christchurch during the quake and just missed being flattened by a falling building.

Christchurch, despite the damage and loss of life, fared remarkably well.  Old brick buildings came down and a couple of modern ones as well.  The suspicion at this point is that the modern buildings  collapsed  because of the soil they were built on rather than any lack of compliance with the building regulations.  Our Prime Minister has ordered a full enquiry to get to the bottom of the situation and to see if the earthquake proofing regulations must be updated.  Rescue teams from around the world have said that this is the 'best' disaster they have been to in terms of the organization and support from the entire country.  Compliments to our leaders past and present.

Despite fairing "remarkably well" it looks as if around a thousand commercial buildings will have to be demolished and that doesn't include residential properties.

Now we have the task of rebuilding Christchurch.   This includes both commercial buildings and at an early estimate, 10,000 dwellings.  Some heritage buildings will undoubtedly be saved but overwhelmingly we will have to build anew.  So what do we want to see in Christchurch.    Below is a hodge podge of ideas in no particular order - brainstorming if you like.  I will keep adding to it and if you want to have your say, please make a comment.

The urgent aim at present is just to get the city up and running.  It seems very harsh to ask the planners to use this opportunity to create a better city.  However, if we don't do so, we will end up with a patch work and much greater expense if we decide to incorporate any of the following ideas later.  It will be far less expensive to incorporate them now while the infrastructure is upside down and a huge amount of energy is being put in to restoring Christchurch.

Solar Power*
Just think of the price reduction for quantity we could achieve if we decided to put solar panels on the rooves of every new building or better still, if the technology is up to it, to use solar panels as the roof (saving the cost of the conventional roof).  Here I'm not talking about a few panels per building but rather the north facing slope of every new roof completely clad in panels. Technology is well under way, also,  that turns windows into solar panels.  Every north facing window which receives the sun could incorporate this technology.  The reduction for quantity would extend to all the ancillary equipment such as inverters, grid compatibility electronics and so forth.  We should get our best people from Pharmac** on the case.

*In March 2011, Japan announced that it is thinking of requiring every new building in Japan to be clad in solar panels.  This follows the decline in generating power due to Fukushima.

**Pharmac is our medicine buying organization which results in the medicines we use in New Zealand costing us as little as a tenth of what other first world countries pay (much to the disgust of Big Pharm in America)

With the huge size of the investment involved, we could afford to send a couple of our best engineers on a world tour, starting with and ending with Germany, to thoroughly investigate the state of Solar technology at present.  At the same time, we could introduce smart grids to Canterbury.  It has to come sometime, and  better sooner than later.  The same engineers could examine the state of smart grids in the world.  There are many problems for power companies associated with the introduction of smart grids and with the incorporation of large sources of renewable energy.  The sooner we get a handle on how to manage smart grids and multiple inputs of energy from small generators, the better.   Christchurch could turn into a major net generator of electricity.  We would soon be running electric  cars which are entering the market this year, with stably priced electricity from our own rooves rather than with ever more expensive petrol and too-valuable-to-burn coal. Doing the introduction of solar on this scale would introduce a high level of standardization which would keep the price down for later introductions of solar.  It would  decrease the cost for anyone with a house that wanted to retrofit solar.

And how about a solar water heater for every new house.  An often heard estimate is that a third of the electricity used by a house is to heat its water.  Again, huge economies of scale could be achieved by using  a standardized water heater for every new house and we produce these in New Zealand.  To the government I say don't you dare even think of buying these overseas.  We have our own solar water heater industry.

Roof gardens
On rooves not clad with solar panels, how about roof gardens.  Many cities are incorporating these now and they can be decorative, making a pleasant place to sit and sip coffee or can even be growing salad greens, tomatoes and herbs for downstairs restaurants.  The technology now exists to use very light rooting medium in combination with hydroponics. In some locations, one could even have walk ways between buildings, eliminating the necessity to even come down to ground level to go from, say a cinima to a restaurant

Wood Construction
One of our MP's, Jim Anderton  suggested rebuilding with wood.  In case you are thinking in terms of 4 X 2 house construction, this is not what is talked about.  Laminated wooden beams are incredibly strong and resilient and wooden buildings can be built many stories high.  Ply wood cladding, glued and fastened to structural members adds a huge amount of extra strength.  Wood is extremely flexible and has great vibration dampening properties.  Wood is a particularly easy medium to use to achieve whatever style is desired.   Wood construction can be made virtually fire proof, vermin proof and UV proof.  I don't think there is any question that wood construction should be very seriously considered and investigated.  However, there is a potential problem.

The hidden cost of contracting such work overseas is immense.  Instead of buying overseas, let us become the world center for building reconstruction for the earth quake damaged areas of the world using our considerable wood resources to sell know how and value added products.

Insurability
There will  be a temptation to do a patch up job on some buildings, notably some of the damaged dwellings.  Come the next earth quake, they will be further weakened or destroyed.  Insurance companies would be foolish to insure such buildings.  The construction must be carried out to a standard such that any building passed will be re insured for the same premium that a similar building in a different location would attract.  This must be the criteria for the necessary standard of repair.

For private houses, one can build, for instance, on floating foundations*.  With a floating foundation, if another quake does come and the house tilts, it won't break. Houses built on floating foundations won't have liqufaction coming up through the floor.  A floating foundation must be strong enough that if it tilts, it can be releveled.    Above all, any rebuilt houses must be earthquake proof.

*  A floating foundation is a reinforced cement slab with reinforced beams underneath, all cast in one pour.

Overhead Power Lines
It is very nice having buried power lines but not very practical for an earth quake prone area.  Overhead lines are far less vulnerable to damage and are far more quickly and cheaply repaired than buried lines.  Some work might be done to reduce the visual impact of overhead power lines but putting them underground should not be considered.  If there was some practical way of having water and sewage above ground, that would also be desirable but unfortunately this is probably out of the question.  Keeping the power on after a disaster greatly alleviates the suffering of the effected population.  Having electricity can help alleviate the lack of piped water and sewage.   With power available, one has cooking, heating, water sterilization, and communication.  Power tools can be used to repair damage and water can be pumped if a source is available.

Car Charging Points
Electric cars are coming to the market this year (2011).  To attain the considerable benefits from electric cars, there must be convenient outlets to charge them.  In the rebuild of Christchurch, much road work will have to be done and streets will be dug up to repair sewage, water and electric lines.  This is a perfect opportunity to put in the necessary cables which will allow cars to be charged where there are parking meters today and in the parking lots of businesses.  They should be card swipe units which allow you to dial how much charge you want and at what priority.  In addition, lots should be set aside for the construction of battery changing stations a la Better Place.  Whatever the case, lets get the necessary power lines installed while the roads are being dug up anyway.

Sorting out Road Names
How about, while we are at it, sorting out the names of the roads in and around Christchurch.  Some roads change their names as many as 5 times as you drive along them.  Work out some system of deciding which of these names is to be used and change all the others to fit.  Christchurch is a confusing town to navigate in.  The CBD is nicely squared off but outside of there, the roads radiate out in every which way.  Knowing, for instance, that when you are on Pages road, Baldwin's road, or Aldwin that you are actually on Ensors would greatly aid navigation.

Thermal Mass in Houses
The insulation of a house is only one factor in making it comfortable to live in.  A great deal can also be achieved by increasing the thermal mass inside the house and putting the insulation outside rather than in the walls.  This evens out temperature variations and retains cold or heat that you have spent money in achieving.  If you are using free heat by allowing sun to shine into windows, this heat is retained overnight.  If you are cooling by allowing cool air in at night, this is retained through the day.

Heat Exchange Windows
It is highly desirable to have a high level of air exchange in a house.  This, however, wastes heat in cold days or wastes "cold" in  hot days.  You pay money to heat or air condition your house.  Windows exist which transfer heat between outgoing and incoming air.  They could be considerable improved by using counter-flow technology.  Such windows allow a good exchange of air while maintaining the temperature you are trying to achieve in your house. New Zealand could become the leader in this technology while improving the livability of New Zealand homes which are famous for dampness, mold and poor thermal characteristics.

Large Hats
A house avoids a lot of the problems of leaks simply by having a large overhang on the roof.  It is not the whole solution but is an important component.  Put in the building regulations the requirement for a minimum required overhang.  This might be larger for two floor houses than for one floor houses.  While we are at it, legislate for only long run roofing.  It is light, strong, easily replaced, only dents if something falls on it and "bridges" rather than collapsing if the whole house falls down.  It needs lighter underlying construction than ceramic or cement rooves and hence makes a more earthquake resistant dwelling.  Who in their right mind would want a great weight of fragile cement above them when an earthquake hits.  Better still, make the roof cladding out of solar panels.

Chimneys
It hardly needs stating that brick chimneys are out.  If you must have the style get one of the fibre glass ones with a steel flue inside.   If someone insists on a brick chimney, cancel his insurance.  The fire service wasted thousands of hours taking down brick chimneys when they should have been doing far more vital work.  While we are at it, brick chimneys should be eliminated from all of New Zealand.  No place on our islands is immune from earthquakes.  Cut the gorgons knot.

Feed In Tariffs - how to structure

For anyone not familiar with the term, Feed in Tariff  (FIT not surprisingly) is the money the electrical company pays you per unit (kWh) that you generate and send down their wires.
 
A most interesting system of feed in tariffs exists in Germany today. The government has legislated a feed in tariff equal to about 3 times what the same customer pays for electricity. The electrical company charges a little more to all customers and uses this money to subsidise the owners of home generation systems. Houses and businesses have two metres. One metre records the amount they use, the other how much they produce. You don't get the three-times rate for the difference between what you use and what you produce but on the whole amount you produce. The German government has guaranteed that this situation will continue for 20 years from the date of installation. To induce people to get in early, the small generator gets the rate for his power generation that is extant in the year he installs his solar unit and this rate decreases from year to year. Thus people who installed solar in 2004 are getting 55c per unit until 2024 while people installing their unit this year (2008) will get 45c per unit until 2028. By 2011, the rate may be around 35c per kWh (kilowatt hour)

The system is obviously not sustainable. A company can't be buying a product and selling it for a third as much. Moreover, as more and more people put solar panels on their roves or wind turbines in their garden, the power company will have to charge the conventional customers more to pay off the generating customers. However, you have to hand it to Germany. What they aimed at has worked and at a bargain price when compared with building coal fired power stations.  Best of all it is  without any involvement of the always inefficient government tax system. (well, maybe in Germany it is not inefficient.  In fact in this link you will see just how clever the German Tax Department is.)

Germany has clearly recognized that in the not too distant future, the cost of power from fossil fuels will start to increase exponentially, due to demand exceeding supply and due to increasing compliance costs. With the German scheme of feed in tariffs, they have created a renewable solar-electric generating capacity equal to the output of about 4 large coal fired generating stations (over 13 GW as of the end of 2007) and growing day by day. With energy being a large part of the cost of any product, when the rest of the world is trying to play catch up, Germany will have megawatts of stably priced, renewable energy for her industries.  This in a country with less that 2 peak hours of sunshine per day.

Here in New Zealand, I suspect, (and hope) we won't go for the subsidy model that Germany is using. Part of this is philosophical-historical. Not so many years ago, our agriculture was one of the most heavily subsidized in the world. People didn't farm crops, they farmed subsidies. With great foresight and more than a little courage, the government of the day decided to scrap all agricultural subsidies. We went cold turkey and it worked. After some admittedly hard times, our farmers have become lean and mean and of most importance, their decisions are now based on economic reality rather than how to play the system. They now compete all over the world against subsidized agricultures and compete very successfully. (or would if the Americans would pay more than lip service to their professed free trade policy)

I would like to see a much different system. It is simpler, more easily understood and sustainable. Keeping in mind the law of unexpected consequences, as a first suggestion, it would be structured as follows.

There would be only one meter in your house or business and the electricity you generate would simply turn the meter backwards.  The two meter system is a scam. The electrical company would structure its charges (as they do at present) with a fixed charge and a charge per unit (kWh) used. There have been many names for this fixed charge but for the sake of this discussion lets call it a line charge. This is the amount you pay for the privilege of being connected to the grid. This is reasonable as the electrical distribution company had to build the distribution system and has to maintain it. Now here is where we have to be a bit careful. The electric company could structure this differently for people just using electricity and for people using and generating electricity. For the generators, they could have a very large fixed cost and a very low power rate for power used or generated. For the non-generating customer the reverse. This is where the government must step in and block this possibility. They must simply legislate that whatever the charge structure the power company decides on, it must be the same whether you are generating or not. Then if the generating company tried to charge a huge line charge and a small per-unit charge, the ordinary customer could use huge amounts of power for almost a fixed cost. If they charged a very small fixed charge and a large per-unit charge, the generating customer would make lots of money. Structured so that the system is the same for both types of customer, the system is reasonably self regulating since it is in the interest of the power company to maximize its profits by a middle of the road approach.



There is also no need for the power company to send out bills every month (or payments for that matter) to the user-generator.  The amounts either way will be small and a financial reconciliation can occur once each year.  Ordinary  customers get billed as usual. So what are the implications of such a system.

Firstly, there is no need for the installation of any extra meters by the power company which they will charge to the customer. This also eliminates the VAT you would have to pay on the extra meter.

Secondly, the power company doesn't have to service a developmental loan for installing new power stations. All the capital costs fall on the private individual. The only extra wiring needed is the wiring associated with the power generating unit. The customer must have in place all the equipment that makes his system compatible with the electric company and that is the end of it.

Thirdly, this system is sustainable and good for the power company. The power company is "buying" power during the day when they charge the greatest amount for their power and the power, on average, is being generated closer to the end user than is the case with remote, high output power stations. Getting power when the demand is greatest and reducing their line losses increases their profits.

Fourth, the system can be left in place for ever and doesn't have to be changed at some time in the future as with the German system. Stability of system allows for long term business planning and is greatly encouraging to businesses.

Fifth, the power company also gains on the Internet effect. Diffuse power generation is less vulnerable to line outages than high-power point-sources.

Sixth, the power company still makes money on their line charge commensurate with the cost of maintaining the lines.

New Zealand is an innovator in so many ways. Hopefully we will also be innovative with Feed In Tariffs.

One thing we must guard against at all costs is double metering. In Germany, even, now when the government is trying to encourage as much uptake of solar electric as possible, they are adding the revenue made by the small generator to his income for income tax purposes. For someone with a high salary, the marginal rate is 46% and there is a further 5.5% Unification surcharge. They are also charging GST (VAT/sales tax) at 19% on every unit of electricity the customer uses. Note that these charges are  not on the difference between what you use and what you produce but on ever kWh you use and every kWh you produce.   When the unrealistic FIT system ends, the small generators are going to find they are still paying quite a bit for their power even if they are generating as much as they use. In fact, depending on their tax bracket, the small German generator would have to produce 2 to 3 times as much power as they use in order to reduce their net power bill to zero. Think about the cost of servicing the loan they have to take out to buy this extra large system. Think about the GST they pay the government for this larger-than-needed system.   If someone does decide to put in a system which is larger than they need for their own use, they should be allowed a fair return. For the sake of argument, let's say 80% of what the power company charges for power at the time of generation.

The correct system of metering and Feed In Tariffs which is fair to both power company and customer and which is sustainable will be a great encouragement for the uptake of renewable energy by the small generator and won't have the customer wake up one morning and realizing he has been scammed.

Pension Funds and Solar Panels

Some governments say that the main purpose of a pension fund is to provide for us in our retirement. They sometimes hint, that since it is a savings plan and not an investment, we shouldn't really expect much of a return (Yeah right!!!!) and should be grateful for any contributions or tax concessions they make. Since pension funds are "for our own good", lets take them at their word and see if they will "put their money where their mouth is". What about allowing us to use funds from our pension fund for putting solar water-heating panels and/or solar electric panels on our roofs or for that matter, to insulate our houses.

The oft quoted expenditure for water heating is about a third of a typical electrical bill so if we install a solar water heater, all this saved money will be available for retirement saving, making us even better off in our retirement. The typical pay back time for solar water heating is between 5 and 10 years and the earlier we install it the more we will earn. Moreover, when we retire, the children are likely out of the home so we can probably get all our hot water needs without having to use supplementary electricity. If there was ever a use of our pension money that would leave us better off in our retirement, this is it. And what about installing Solar-Electric panels. Here the benefit is even greater.

With Solar-electric, again we score well before retirement. The one time investment will pay dividends all through our life, leaving us more money from our income for saving. When we retire, with the kids out of the house and electrical demand reduced, we may even be receiving a net income from our solar panels. Our own private pension plan. Even better, since our excess generation is turning the metre backwards, we save on our tax bill. When we buy electricity, we pay GST(VAT). Since we are reducing our payments we pay less GST.

We also gain on the other end. If you sell something, you pay income tax on your earnings. Here you are simply turning the meter backwards. In so far as it is balancing your electricity use, it's neither income or expenditure so you don't pay tax on this money. Better and better.

The expense reduction I am really looking forward to, though, is when purely electrical cars with, say, a 200 km range and a reasonable price tag, come on the market. Every home will have a 'petrol station' on the roof in the form of their solar panels. The car gets plugged in and the house "fills the tank". Add solar panels to the roof and hood of the car and you could perhaps add an extra 10 to 20km of driving for a day in the sun.

A further benefit of solar electric will occur to the canny retired couple who are now at home during the day. They will be able to do their bread making, hovering, laundry etc during the day when the sun shines. This will avoid the price differential between the buying and selling price of their electricity#. Therefore it is to the advantage of the house owner to use electricity when they are generating their own. The electricity company shouldn't have it all their own way, though. A household will be producing power during the day when the electric company charge the highest rates. Their payment to you should reflect this. Also with diffuse power generation all over the country, generation will be, on average, closer to the user so line losses will be less. This should also be reflected in the payment to the domestic generator.

#There will always have to be a price differential. The power company will have to charge you more for a unit of electricity than what they pay you. After all, they must maintain the distribution network

Solar panels, whether electrical or water heating, are a true retirement saving plan but in addition they fulfil a number of national goals. These include reduction of our carbon foot print, reducing the need to build more unsightly power pylons (power generated diffusely and hence nearer to the users), reduced need to flood more river valleys, reduced negative balance of payments due to less fossil fuel imports, reduced air pollution from thermal power stations and vehicles, reduced chance of power breakdowns in times of national emergency (inter-net effect) and reduced health bills from air pollution. With such a long list of beneficial effects combined with the obvious retirement benefits, I'm sure the government will approve using pension funds for domestic solar panels. Let's see if your government is really serious when they advertise that your contribution to a pension plan is for your own good.