Leading UK renewable energy specialists
0800 848 8650

Sitemap

Renewable Energy Systems from Solar Essence: solar photovoltaic pv, air & ground source heat pump, solar thermal heating, domestic wind turbine, rainwater harvesting, underfloor heating uk

est energy saved by our customers to date

solaressence® evacuated collectors

In 1893, Scottish physicist James Dewar invented a double-walled vessel with a vacuum-insulated gap - the thermos flask. Based on the principle of the thermos flask, already in 1909 Emmet developed evacuated tubes in order to make solar power usable. Even today, his patents from that time are the basis for modern evacuated tube technology. However, the efficiency of this old and well-known technology of the thermos flask could be brought to the highest level only with the help of modern coating technologies and highly selective layers.

The technology - today

The solaressence® range of evacuated tube collectors consists of 3 main components.

evacuated tubes,
CPC mirrors, and
collecting box with heat transfer unit.

The evacuated tube

The evacuated tube is a product that is optimised in geometry and performance. The tubes are composed of two concentric glass tubes which in each case are half spherically closed on one side and fused together on the other side. The gap between the tubes is evacuated and afterwards hermetically plugged (vacuum insulation).

In order to make solar power usable, the internal glass tube is provided on its external surface with an environmentally friendly, highly selective layer and thus designed as an absorber. This coating is thus protected within the vacuum gap. It is an aluminium nitrite sputter layer which is characterized by very low emission and very good absorption.

The CPC mirror

In order to increase the efficiency of the evacuated tubes, a highly reflecting, weather-proof CPC mirror (Compound Parabolic Concentrator) is placed behind the evacuated tubes. The special mirror geometry ensures that even at unfavourable irradiation angles direct and diffuse sunlight falls onto the absorber. This substantially improves the energy yield of a solar collector. Unfavourable irradiation angles are given at diagonally incoming light (azimuth angle) (no south adjustment of the mounting area, sun progress from east to west, diffuse irradiation).

Collecting box and heat transfer unit

The insulated collecting and distribution pipes are located inside the collecting box. The advance or return connection can take place alternatively on the left of or on the right. In each evacuated tube there is a U pipe with direct flow-through that is connected in such a way to the collecting or distribution pipe that each individual evacuated tube exhibits the same hydraulic resistance. This U pipe is pressed to the inside of the evacuated tube with the heat guide plate.

It all adds up to make the solaressence® range of evacuated tube collectors one of the most advanced available in the market place today.

absorber plate protected from wind and adverse weather providing perfect insulation
vacuum provides long life
all weather working capability provides energy all year round
saving you even more money
highly efficient advanced design

technical

It is a strict company policy that we do not quote percentage savings or payback times. This is simply because they are so variable from each installation to another. How and when you use your hot water and central heating as well as how efficient your existing system is are all important factors that effect these.

The Solar Trade Association guidance contained within their website states ‘In terms of costs you would expect to save between 50 -70% on your annual heating costs, as the more hot water used the greater the saving. For a family of four, a well designed solar water heating system should contribute around I,500kWh and 2,000kWh, which will be equivalent to 50 to 65% of the household’s water heating energy needs. The monetary value of this saving will depend on the type of energy displaced.’

It must be noted that this guidance applies to hot water only systems and that the 50-70% annual heating savings claimed does not extend to space heating as you may assume from how it reads, just hot water heating. Solar Essence simply do not attempt to make such claims. We rate our systems in expected kWh out put from the collectors.

However if you assume an average home uses 3000 kWh for it’s yearly hot water demand, and you use 2500 kWh to heat your water. If you gain 3200 kWh from your solar system - the savings are obvious. How you store and use your hot water as well as the efficiency of your heating controls are also very important when considering potential savings.

Put simply Solar Essence do not just install hot water only systems, the main core of our business is our Dual Solar Heating Systems that are able to combine all energy inputs from all sources. These dual systems are very different in specification, installation & operation from standard solar hot water systems, and enable us to over specify solar input. Standard sized system outputs range from 978kWh for our smallest hot water system to 2604kWh. Standard Sized Dual systems range from 1953 kWh to 5208kWh. We also undertake many totally bespoke sized installations where we have installed up to 15000kWh systems for domestic use.

Energy Conversions:

1 kWh = 3412 Btu = 3600000 Joules = 0.03412 Therms

Calorific Values: Natural Gas = 10.97 kWh/m3 Light Oil = 11.53 kWh/litre Butane = 13.69 kWh/kg Coal = 7395 kWh/t
(figures assume 100% boiler efficiency)

OEM FLARE Collectors

SERIES		ESSENCE CPC 6 INOX	ESSENCE CPC 12 INOX	ESSENCE CPC 18 INOX
Number of evacuated tubes		6	12	18
ηº in relation to aperture, EN 12975	%	64.2	64.2	64.2
a¹ with wind, in relation to aperture	W/(m²k)	0.89	0.89	0.89
a² with wind, in relation to aperture	W/(m²k²)	0.001	0.001	0.001
Kθ,trans (50°), in relation to aperture		1	1	1
Kθ,long (50°), in relation to aperture		0.9	0.9	0.9
Yield forecast (reference location Würzburg, Germany, aperture area 3 m²)	kWh/m²a	651	651	651
Yield forecast (reference location Würzburg, Germany, aperture area 5 m²)	kWh/m²a	589	589	589
Grid dimensions (length, height, depth)	m	0.70 x 1.64 x 0.1	1.39 x 1.64 x 0.1	2.08 x 1.64 x 0.1
Gross surface area	m²	1.15	2.28	3.41
Aperture area	m²	1.0	2.0	3.0
Collector contents	l	0.9	1.8	2.6
Weight	kg	19	35	52
Max. working overpressure	bar	10	10	10
Max. stagnation temperature	°C	272	272	272
Connection diameter, clamping ring	mm	15	15	15
Sensor sleeve	mm	6	6	6
Collector material		Al/ stainless steel/ glass/ silicone/ PBT/ EPDM/ TE
Glass tube material		borosilicate glass 3.3
Selective absorber coating material		aluminium nitrite
Glass tube (Ø ext./Ø int./wall thickness/tube len.)	mm	47/37/1.6/1500
Colour (aluminium frame profile, powder-coated)		RAL 7015
Colour (plastic parts)		black
Thermal shock test	ITW test no.	06COL513/1
Hailstone test according to DIN EN 12975-2	TÜV test no.	435/142448
Other tests and approvals		EN 12975, RAL UZ 73, Solar Keymark · ISO 9001
DIN CERTCO - Register number		011-7S113R

SERIES		ESSENCE OEM 20 FLARE	ESSENCE OEM 30 FLARE
Number of evacuated tubes		20	30
ηº in relation to aperture, EN 12975	%	56.1	56.1
a¹ with wind, in relation to aperture	W/(m²k)	1.61	1.61
a² with wind, in relation to aperture	W/(m²k²)	0.004	0.004
Kθ,trans (50°), in relation to aperture		1.17	1.17
Kθ,long (50°), in relation to aperture		0.93	0.93
Yield forecast (reference location Würzburg, Germany, aperture area 3 m²)	kWh/m²a	559	559
Yield forecast (reference location Würzburg, Germany, aperture area 5 m²)	kWh/m²a	506	506
Grid dimensions (length, height, depth)	m	1.47 x 1.64 x 0.13	2.20 x 1.64 x 0.13
Gross surface area	m²	2.40	3.60
Aperture area	m²	1.75	2.62
Collector contents	l	1.1	1.65
Weight	kg	49	73.5
Max. working overpressure	bar	8	8
Max. stagnation temperature	°C	225	225
Connection diameter, clamping ring	mm	22	22
Sensor sleeve	mm	6	6
Collector material		Al/ stainless steel/ glass/ silicone/ PBT/ EPDM/ TE
Glass tube material		borosilicate glass 1.6
Selective absorber coating material		aluminium nitrite
Glass tube (Ø ext./Ø int./wall thickness/tube len.)	mm	47/37/1.5/1639
Colour		stainless steel
Colour (plastic parts)		black
Thermal shock test	SPF test no.	C782QPEN
Other tests and approvals		EN 12975 1&2, ISO 9001

CPC INOX Collectors