Are you better off investing in solar water heating than putting money into a savings accounts?

Unless you are  willing to invest in a high risk bond in a far off land and potentially lose all your money (all though option is no longer available due to the collapse in the Icelandic banks and the credit crunch) you will have to choose a UK based bank or building society (which have not been so financially secure recently due to the credit crunch).

The current domestic savings products are earning about 4.5 percent gross interest on a bond and after a tax of twenty percent or forty percent for a higher income rate earner this will amount to a net interest rate of 3.6 percent for the lower tax band and 2.7 percent for the higher tax band.

When you consider that this would mean that you would only earn  £108  or £81 for the higher tax band on  an investment of £3000 isn’t it worth considering another option.  For £3000 you can install solar water heating that can add top the value of your property and saving up to 25 percent of your overall heating bill which would prove attractive if you use gas central heating and even more attractive if you are using the more expensive fuels such as oil and electric boilers.

Furthermore the Bank of England are going to meet in early   January of 2009 and are expected to cut base rate by another 0.5 to 1.0 percent which would mean that savings rate may fall to 4 or 3.5 percent on a bond which would mean at worst that you would only earn  2.8 percent net or 2.1 percent net on a higher income band which equates to

£84 interest for a lower band income earner and £63 for a higher income band earner now the fuel bill savings associated with solar water heating must be an even more attractive proposition compared to the savings rates earned with your bank or building society.

In addition to this we must also consider the benefits that solar water heating can bring with regards to the recent events happening between Russia and the Ukraine and its effect on the security of gas supplies to the UK.  Due you want to secure your hot water heating supplies and no longer be held to ransom by Russia!

A direct solar heating system uses the existing hot water tank.  The cold water supply to the solar  panel is drawn from the cold water feed pipe to the existing hot water cylinder. This is the pipe that runs from the header tank down to the bottom of the hot water cylinder. This water is then heated by the panel and then fed back to the water cylinder y a pipe that connects to the hot water output that comes out of the top of the cylinder both connections can be made easily using a t piece.  The disadvantage with this system is that the solar water heating panel will only allow you to heat up the top of the hot water cylinder due to the existence of thermoclimes. A may have come across a thermoclime in  the sea before where you go swimming and find a freezing cold band of water around your legs but the water above this is warm.  It is for this reason that all existing hot water cylinders have the coil at the bottom for the traditional boilers and have done for years.   One further floor with these systems is that you obviously cannot add any fluid to stop freezing as you would loose it down your plug hole the first time you turned your taps on so these systems rely on using plastic piping that can expand in freezing conditions but of course if you have allowed the pipe to freeze your solar water heating panel can no longer be supplying any free energy! Furthermore, the temperatures reached by solar water eating panels can be in excess of one hundred and forty Celsius which also brings into question the lifespan of plastic piping under these temperatures.

To sum up a direct system is faster for the installer to fit and should only take one day and is far more profitable for them as they do not have to supply a new tank and they have saved on a days installation but it will not work anywhere as well as an indirect system and will not work under freezing conditions as it merely allows the pipes to freeze and top the supply of hot water and the lifespan of the plastic pipe under the extreme temperatures is questionable.

Indirect solar water heating panels

An indirect solar heating system uses a secondary coil in a new hot water cylinder the new coil is places at the bottom of the hot water cylinder so that it operates like a traditional boiler by avoiding the issue of thermoclime and heats the entire body of the hot water unlike a direct system that just heats the top of the tank it also has the added advantage of being able to operate in winter because it uses its own sealed system containing high heat transfer fluid that can withstand freezing temperature that runs in a loop from the solar  heated panel to the secondary coil in your new tank and back up to the solar heated panel.  The systems should only take two days to fit, the first day is used to switch the hot water cylinders and get the existing system working again and the second day to fit the solar water heating panel and connect to the panel to the secondary coil in your new tank.

Recently I have noticed people trying to create a indirect system using a secondary coil inserted through the emersion heater port at the top of the existing hot water cylinder.  Although this saves on the cost of replacing the hot water cylinder it suffers the same problems as the direct system where you are confronted by thermoclimes and can only ever heat up the top of the cylinder leaving the bottom of the hot water cylinder cold.  I have seen one cylinder that does have an emersion heater port at the bottom of the cylinder (Megaflow).  But I have yet to find an adapter coil that can be inserted through this port that matches the large surface area of the curly fin coil supplied in the brand new cylinders.  You would need an adaptor coil in a large C shape to try and generate the same heat energy of the new hot water cylinders with the secondary coil included and the only ones that I have found have looked very similar in area to a emersion heater so they would not transfer that much heat energy from the solar water heating panel.

To summarise the indirect system is more expensive but actually works and would work all year around  but only if used in conjunction with a new cylinder, placing an adaptor coil at the top of the cylinder suffers the same problems as a direct system (thermoclimes) and a decent adaptor for exiting cylinders which have an immersion port at the bottom of the cylinder does not exist and because of the surface area required even if it did exist it maybe quite hard to fit.