Solar Made Life Easy: Question & Answer : Part III

Question:  
 

Is it possible to incorporate Solar PV panels into a south facing conservatory roof?
     Michael Churchman

Answer: 

Yes it is possible, but of course that will cut down on the amount of sunlight shining into your conservatory.It also depends on the amount of panels you plan to fit to your roof. A large panel weighs in the region of 18kg and so there may be weight limits if you wish to fit lots of panels. To secure the solar panels to the conservatory roof, you would probably be best to bond them to the roof although it may be possible to have special mounts fabricated for the purpose. Your best bet would be to choose which solar panels you want to work with, get the physical specifications of the panels (height, width, depth and weight) and speak to your conservatory supplier to see what they recommend.

Solar Questions & Solar Solutions

Question:   
 

What do you think about feed-in tarrifs?
     John Newman

Answer:

Now there is a big question. How long have you got?
I question what the Government hope to achieve with feed in tarrifs in terms of overall carbon reduction. I also feel that with the proposals as they stand, the 'early adopters' who have already installed solar stand to loose significantly, which is unjust.
However, from the model seen in countries like Germany and Spain, it is clear that a feed in tarrif this scheme will encourage the short term take up of solar for grid-tie applications. Whether that is the best application for solar depends on a number of factors, such as geographic location and how the local electricity is generated on the national grid.
Personally, I believe the plan is flawed and a better solution would have been to boost the renewable obligation certification scheme (ROC) by improving the funds available and reducing the paperwork and administration for solar home owners to go through.
This would also have been of much greater benefit for off-grid solar systems, which have a much greater potential to reduce carbon emissions over grid-tie systems.

Solar Made Life Easy: Question & Answer : Part II

Sun Questions & Answers

 
Question:  


I have a question, we add the voltages of panel together and add the power( in watts)of each panel together you calculate the max. amount of power and voltage the solar will generate, and on other hand in one of the book its written that 4 panels, each on have 12V and power 20W and when connect in series it will be 48V, 80W array. I think in this case, we have to connect in parallel with another 4 panels with the same V and W to get 48V and 80W.
Best regard
     
Answer: 

With regards to your question, when you connect solar panels in series, both the voltage and the power increase, whilst the current remains the same. When you connect solar panels in parallel, the power and the current increase, whilst the voltage remains the same.
Let me explain another way, using the example of a 12v 12w solar panel (I'm using 12w because this equals 1 amp at 12v, which makes the maths easier).

If you take one 12v 12w panel, your solar panel provides 1 amp of current at 12 volts. If you take four
12v 12w panels and connect them in series, the power and the voltage is multiplied by four - so you have 48v at 48w, but your current remains the same - 1 amp.

If you then take four 12v 12w panels and connect them in parallel, the power and the current is multiplied by four - so you have 12v at 4 amps, but your voltage remains the same - 12v.

I hope this answers your question.

 

Solar Made Life Easy: Question & Answer : Part 1

Sun Questions & Answers

Question: 

Hello I have at spa/hot tub which holds approx. 1000ltrs water just wondering if you think it viable to incorporate a heater to the system to keep water temperature at a set temperature . the system has a 1.5kw heater witch switches on and off automatically when temperature drops 1 degree . full system running consumes 2.5kw (pumps and lights etc. ). Rather than having a 1.5kw heater switching on and off when needed I thought a smaller heater running continuously from free power might be worth doing even if it only helps a little. Any help or suggestions would be most welcome.
  
Answer:

Solar power can definitely help you here... but I would not recommend solar electricity: you would be better off investigating solar hot water systems.

Photovoltaic panels (which generate electricity from sunlight) tend to be between 6% and 15% efficient whereas solar hot water systems can be up to 70% efficient and tend to be cheaper to buy as well - at least in DIY form, especially if you spend some time shopping around for the best prices.

A solar hot water system incorporating a thermal switch should go a long way towards reducing your energy consumption. Exactly how big your system would need to be would depend on a number of factors - specifically whether your spa is indoors or outdoors; what months of the year you want to use your spa; where about in the world you are based.

Meanwhile, you can reduce your current electrical consumption by using energy saving lighting - I recently saw a swimming pool lit by LEDs which looked stunning and are extremely energy efficient.