I am looking at the max 1.3kW heliostat called H1 by Light Manufacturing Systems, USA.
The suggestion is to source the mirror locally, it needs to be of ACP material as defined above.
Does anybody know of a manufacturer/seller? Thanks
Source in Aust. for "aluminum composite material (ACP) with a mirror finish"
(8 posts) (4 voices)-
T-roy
MemberHi Vauban,
I work for a Sign Manufacturer/ Theatrical Set Construction in Wollongong, NSW and we use ACP all the time. We get our ACP, Mirrored and all sorts of colours, from Mulfords Plastics in Sydney. Pretty sure its all made in China.
Good Luck,
T-roy.
Posted Tuesday 8 Aug 2017 @ 7:38:37 am from IP # -
arttt
Memberbit of a late reply, and not what you are directly asking.... but relevant.
That H1 heliostat is listed at US $2,271
I dont know what you have intended for it but if you are using it for heat compare it to solar PV
https://www.solarchoice.net.au/blog/residential-solar-pv-system-prices-july-2017The heliostat might be the right choice for what you are doing but it might be simpler/cheaper to put up some PV and run a cheap electric heater or heat pump.
Posted Monday 21 Aug 2017 @ 3:09:26 am from IP # -
Vauban
MemberThanks to T-roy and artt for their useful replies;yes, the idea was to apply 1.3kW heat output direct from heliostat through a "normal SHGC" window without presumed efficiency losses caused by PV panel conversion from solar radiation to DC and AC electricity and then back again to space heating, if I just ran a heat pump or reverse cycle AC off PV panels. That is, if my PV panel is hit by 1kW/sqm, how much heat does it produce at the end of the heat production chain?
The impact point of the heliostat light through the windows would be internal solid brick walls acting as thermal mass to hopefully iron out diurnal fluctuations of ca. 13 - 2 C in July.
But dollar for watt, I do not know what produces more heat on a day of intermittent winter cloud, PV plus electric heating or heliostat aimed at thermal mass internal walls. I use very little power before space heating, max 5kWh/day.
Posted Monday 21 Aug 2017 @ 5:10:56 am from IP # -
arttt
MemberI think you are in Launceston TAS?
sums below are for that location.
in June the heliostat will see Solar Radiation with it 2 axis tracking of 3.55 kWh/m2/day (calculated with PVWatts) the mirror is 2.3 square meters so that is 8.2kWh per day. The mirror wont be perfect nor will the window that it shines through nor will the tracking as it has to angle to the sun to get the right reflection. optimistically the heliostat might deliver at 80% efficiency 6.5kWh per day in June.
This costs AUD $2866 plus shipping and installation.In June a north facing high tilt angle solar PV system at about 60 degrees gives the best generation of about 2.7kWh per day for a 1kW system (again from PVWatts). To get the same average daily heat output as the heliostat you would need a 2.4kW system which would be about $3500 installed.
Resistive heaters would only be a few tens of dollars.
If you are installing solar anyway installing a bigger system brings the price per watt down quite a lot. You also get to sell or use excess generation for the rest of the year which could save or make you some money.If you paired the solar with a heat pump with a COP of 3 then the solar install could be a third of the size. but factor in that smaller solar systems are relatively more expensive on a per Watt basis. I will let you google the various heatpump options and costs.
Im assuming that you are grid connected to smooth out the demands of the sun v the heating system. There is a cost in doing this depending on the Feed in tariff available.
Im short you are right that the energy conversion efficiency is probably much higher with the heliostat but if you consider the suns energy is free then the interest then turns to finding the cost efficient way to use it.
There are obviously other factors then just cost to consider.
Posted Monday 21 Aug 2017 @ 7:32:49 am from IP # -
Vauban
MemberThank you very much for your superlative detailed sums-based reply, artt, also for the solarchoice URL. Highly useful.
I am not in Launceston actually but in Adelaide Hills, which would increase the kWh figures you give due to higher insolation.
I am currently also wondering if it is possible to instal an air-sourced heat pump with some PV panels to drive retrofitted hydronic heating under the skirting boards. The house currently has just a reverse cycle Mitsubishi legacy AC for heating and the solid brick walls separating the 8 rooms are thermal mass for both good and bad at 310m altitude; the heat pump and PV however would drive only space heating and not a HWS, as legacy LPG bottles feed both an instantaneous gas HWS and a gas stove for cooking.
The gas rings can be lit manually ie no electric power is needed, which makes for great resilience at grid-down.
Posted Monday 21 Aug 2017 @ 8:10:19 am from IP # -
arttt
MemberSuprisingly pvwatts http://pvwatts.nrel.gov/pvwatts.php is giving 8% lower insolation in June for Mt Lofty.
However the solar pv price is much lower in Adelaide then Tassy.
It looks like a 3kW system on a more conventional roof angle of 25 degrees would be a similar price to the heliostat delivered and installed, provide as much energy in mid winter but more flexibility in how you use it, and give you power bill savings the rest of the year.
Obviously I'm just comparing with the heliostat not saying this system will meet your heating needs. How big a heatpump and pv system you need to do that is way off this topic.
Posted Monday 21 Aug 2017 @ 12:21:03 pm from IP #
