Easy to Print SolaPlug Information
Performance of Solar Water Heating Systems
| Performance of Solar Water Heating Systems |
| All solar systems in which a single hot water cylinder or store is
heated by solar and a boiler depend on appropriate timing of the boiler
to achieve good performance. |
| The EST Report "Here Comes the Sun"
http://www.energysavingtrust.org.uk/Generate-your-own-energy/Solar-water-heating/Field-trial-of-solar-water-heating-systems
confirms this. |
| The practice of a dedicated solar volume at the bottom of a twin
coil cylinder is a good way of mitigating the problem, but the EST
trials demonstrate that it is not a complete solution. |
| Proper control of the backup heating timing is essential. |
SolaPlugs fitted into direct cylinders may well have a dedicated
solar volume.
SolaPlugs fitted into indirect cylinders probably will not have a
dedicated solar volume, & these systems will be more dependent on
appropriate back up timing. |
| The overall performances of solar systems
with and without dedicated solar volume are summarised below. Calculated
using SAP2009. |
| Total Cylinder Volume
/ litres |
Dedicated Solar Volume
/ litres |
KWh / year with DSV |
KWh / year SolaPlug |
% Difference in KWh |
| 144 |
48 |
834 |
731 |
-12.3% |
| 168 |
55 |
859 |
756 |
-12% |
| 190 |
70 |
891 |
780 |
-12.5% |
| 210 |
90 |
894 |
798 |
-10.7% |
| 250 |
105 |
894 |
830 |
-7.2% |
| 300 |
125 |
894 |
862 |
-3.6% |
|
Assumptions:
4m² flat plate, south facing, 30deg pitch, no shade, 120m² house,
regular condensing gas boiler less than 10 years old. |
|
SolaPlugs can offer similar performance to twin coil systems, and
excellent value for money. |