How much Hot Water will a Solar Water Heater provide?
Quick Answer:As long as the sun is shining, a solar hot water system will continue to heat your water, even in winter.
Solar hot water systems are designed to deal with periods when there is reduced solar energy, and still meet your household needs.
How can solar hot water provide so much hot water?
At times a solar hot water system can certainly produce more hot water than you need. An important consideration is the orientation of the collector. A collector will absorb solar energy from morning through to sunset, but its efficiency is greatly affected by the angle of the sun and by shade from surrounding buildings and trees.
On a sunny day, the solar collector continues to receive energy even if nobody is using hot water. The storage tank provides somewhere to store that heat for later use.
The size of both the collector and the storage tank is therefore important. A correctly designed system balances the amount of solar energy available with the household's hot water requirements.
How much hot water will a solar thermal system provide?
The capacity of the storage tank doesn't tell the whole story. For example, a tank may have a capacity of 150 litres, but the water inside can be stored at temperatures above 80°C. When it reaches the taps, it is mixed with cold water to reduce the temperature to around 40°C.
This means that for most of the year a 150 litre tank can provide up to 450 litres of usable hot water at the point of use. So although the physical tank may hold 150 litres, the amount of hot water available for normal household use can be considerably greater.
A properly designed and managed system takes both sides of this equation into account: how much energy the collectors can receive and how much hot water the household is likely to use.
Is solar hot water still worthwhile in winter?
Most definitely! A solar hot water system is designed to provide hot water throughout the year, not just during summer. Yes there will be cloudy days, but even in December, Alicante receives on average, enough solar energy to heat your water without using electric.
The water in the tank will not heat up as fast as it does in summer and the final temperature will not be as high. The amount of usable hot water will be reduced but usually will still be enough to meet your needs. If you sense that the water temperature is too low then that is the time to connect the standby electric heater.
The bottom line
Solar hot water systems are designed to make use of the sun when it is available, but there will inevitably be times when there is not enough solar energy to meet the household needs. That isn't a problem in itself because of the standby heater. The important thing is that the system is correctly sized, designed and managed to deal with the conditions in which it will operate.
For homes in Alicante and Murcia, where warm sunshine and higher solar energy are normal, this is something we consider when assessing a solar hot water installation. If you're considering solar hot water for your home, we can look at your available roof space, hot water requirements and the type of system that would be most suitable.
What to do next
Still unsure about Solar Hot Water, but ready to find out more about solar hot water for your home? Contact us today to arrange a free, NO OBLIGATION site visit. We can look at the available space and explain what your options are.