Slide2 : BREAZE Solar Hot Water Initiative Nick Lanyon
Matthew Wood
Slide3 : BREAZE Solar Hot Water Initiative BREAZE Solar Hot Water Initiative
Slide4 : BREAZE Solar Hot Water Initiative MEETING THE KEY CLIMATE CHANGE PRIORITY
What practical steps can ordinary people take to reduce emissions throughout the region on the widest scale possible in the shortest time?
Slide5 : BREAZE Solar Hot Water Initiative THE NO-BRAINERS
Domestically, what is the low hanging, low cost, low emissions fruit?
Draught proofing
Turning down thermostats
Thick window coverings/pelmets
Ceiling insulation
Slide6 : BREAZE Solar Hot Water Initiative O.K. DONE EM’ ALREADY. WHAT’S NEXT?
Solar Hot Water
Why?
Because up to 25-30% of your domestic energy consumption goes into heating hot water
Slide7 : BREAZE Solar Hot Water Initiative THE BARRIERS TO ACTION
“I’ve always wanted to get a Solar Hot Water, but what about…”
COST?
By coming together collectively, we can get a much better price than anything we can achieve as individual, isolated consumers. We can also make the greatest collective emissions savings.
(Answer = Use our purchasing power)
Slide8 : BREAZE Solar Hot Water Initiative RESEARCH FOR TIME POOR/TECHNICALLY CHALLENGED PEOPLE ?
There are about 25 different Solar HWS manufacturers
There are many technical differences between them
(Answer = Get someone else to do it)
Therefore the concept is:
Make it as painless (not brainless) as possible
Make it cost effective as possible.
Slide9 : BREAZE Solar Hot Water Initiative CAVEAT EMPTOR
It ain’t rocket science. On the other hand, we ain’t rocket scientists, either…
Our limitations (time, technical expertise)
Availabilty of non-biased, non-commercial advice
Retaining your responsibility and choice
Fundamentally, we don’t mind what solar HWS you get. The point is to mobilize people to make sure that something ACTUALLY HAPPENS
Slide10 : BREAZE Solar Hot Water Initiative FEEDBACK BEFORE FINAL DECISIONS
Making the research assumptions, values and presuppositions transparent
The need to get a sense of the feeling of the BREAZE majority
Today is about the issues, not the details of different systems
As soon as issues of sustainability enter the equation, the picture becomes more complicated…
Slide11 : BREAZE Solar Hot Water Initiative RULING IN SOLAR HWS– RULING OUT SOLAR HWS: THE CRITERIA
1 Issues of sustainability (embodied energy/reusing current system/life cycle analysis/water dumping)
2 Thermal performance and quality of a system
3 Cost savings/’best deal’ from manufacturer
4 Greatest applicability of system to the greatest number
5 Ease and cost effectiveness of installation
6 Ongoing maintenance
7 Health issues
Slide12 : BREAZE Solar Hot Water Initiative RULE-OUT #1
VITREOUS ENAMEL TANKS vs STAINLESS STEEL/POLYETHYLENE
Slide13 : BREAZE Solar Hot Water Initiative RULE-OUT #1
Vitreous enamel tanks are cheaper than stainless steel tanks ( ~ $400+) but…
No embedded energy savings in manufacturing process (crit. 1)
Ongoing maintenance (replacing sacrificial anode) (crit. 2, 6)
‘Thermal shock’, longevity and inbuilt(?) obsolescence (crit. 1, 6)
Difficulties with recycling – landfill candidates (crit. 1)
Slide14 : BREAZE Solar Hot Water Initiative RULE OUT #2
THERMOSIPHON vs SPLIT SYSTEM
Slide15 : BREAZE Solar Hot Water Initiative RULE OUT #2
Thermosiphoning is a perfectly good way to heat hot water (and has fewer moving parts), but
Many breazers would need to reinforce their roof trusses – extra cost (4, 5)
Electric retrofitters would be buying extra tank unnecessarily (4)
Slide16 : BREAZE Solar Hot Water Initiative RULE OUT #3
POLYPROPYLENE GLYCOL FOR FROST PROTECTION
Slide17 : BREAZE Solar Hot Water Initiative Glycol is used in some systems to protect against frost. It is said to be a food grade substance.
Unlikely that it would breach the heat exchange membrane and get into water system, but no need to take risk (albeit very low) if there are alternatives. (7)
Periodic replacement of glycol and cost of servicing (6)
Slide18 : BREAZE Solar Hot Water Initiative Therefore, preferred options are:
1 Stainless steel/copper/polyethylene (all recycled with and with greater longevity)
2 Ground mounted tank
3 No glycol frost protection
The irony: the presenter personally has all three of the ‘rule outs’!
Slide19 : BREAZE Solar Hot Water Initiative GREENHOUSE EMISSIONS
Electric boost is an real emissions nasty
CO2 Co-efficient = 1.381 kg CO2 per KWh
(eg 12 kwh per day over 10 years = 43.7 MW = 60 tonnes CO2)
Gas boost emissions are not as bad as electric
CO2 Co-efficient = 0.055 CO2 per MJ
Slide20 : BREAZE Solar Hot Water Initiative WHAT ABOUT RETAINING ELECTRIC BOOST AND USING GREEN POWER TO OFFSET EMISSIONS? (green power off peak probs!)
Ken Guthrie (Sust. Vic) reckons…
Energy reduction should be key principle, not just its sourcing
Using electricity to heat hot water is “thermodynamic idiocy”. Generate ‘green power’ locally (sun)
Houses change owners every 5 years (av) and new owners are not guaranteed to buy green power (therefore swap to gas and guarantee better emissions)
Slide21 : BREAZE Solar Hot Water Initiative WHAT ABOUT RETAINING ELECTRIC BOOST AND USING PV’S TO OFFSET EMISSIONS?
Huge waste of pv electricity that should be offsetting the appliances that you can’t heat by using the sun (fridges etc)
Would need a massive pv array ($50,000+) to do HWS and rest of house
However, the perfect, money-no-object system would be solar with electric boost and pv fed electricity (ain’t no gas in our backyards)
Slide22 : BREAZE Solar Hot Water Initiative RUNNING COSTS
Electric – depends on base or base/mid element (night/day tariff)
Gas – again, much more efficient than electric
Slide23 : BREAZE Solar Hot Water Initiative Actual gas bill - Usage pre and post solar system installation (Jan 00 - Jan 01)
Slide24 : BREAZE Solar Hot Water Initiative Meanwhile, in 2007…
Slide25 : BREAZE Solar Hot Water Initiative CONCEPT OF ‘PAYBACK’
Current price of energy makes ‘payback’ fairly long term, however…
Current HWS system will never payback, and replacing conventional with same is entirely negative ‘gain’
Deo Prasad (UNSW Sust. Built Environ.) – recent studies on capital appreciation of property with renewable sources
Slide26 : BREAZE Solar Hot Water Initiative RECS AND REBATES
New home or replacing electric system/gas = RECS (Fed Govt – currently ~ $12)
Retrofitting elec/pre-heating gas/replacing gas = Rebate (Sust. Vic – pretty generous)
THE PROBLEM
The worst emitters (electric) have least financial incentive (if not retrofitting)
The lowest emitters (gas) get best bang for buck (replacing old = rebate AND RECS)
Slide27 : BREAZE Solar Hot Water Initiative Options overview.
Electricity Gas Retrofit to current Replace with
instant. gas boost Replace with
new elec. boost Preheat to current Replace with
instant. gas boost
Slide28 : BREAZE Solar Hot Water Initiative 1. RETROFITTING TO CURRENT ELEC.
Slide29 : BREAZE Solar Hot Water Initiative 1. RETROFITTING TO CURRENT ELEC. PROS
Get Sustainability Victoria rebate
Cheaper to buy in the short term
Re-using what you have
CONS
Not all current hws will be appropriate (spreaders/3yr rule)
Solar tanks purpose built for solar requirements and temp
Current tank may kick the bucket soon
Will still be on electric (not gas) for 6 months of the year
Therefore - higher emissions and running costs COST (30 evac tube - indicative only – no installation)
$2,410 – (15% disc $361) – ($800 rebate) = $1248.97
Slide30 : BREAZE Solar Hot Water Initiative 2. REPLACE CURRENT ELEC. WITH INSTANTANEOUS GAS
Slide31 : BREAZE Solar Hot Water Initiative 2. REPLACE CURRENT ELEC. WITH INSTANTANEOUS GAS PROS
Most efficient from emissions and running costs p.o.v.
Getting system purpose built for solar CONS
Don’t get rebate, only get RECS
Initial purchase cost more expensive due to more features
Don’t re-use old tank COST (22 evac tube - indicative only – no installation)
$5071 - (15% disc - $760) – (RECS ~$520) = ~$3791
Slide32 : BREAZE Solar Hot Water Initiative 3. REPLACE CURRENT ELEC. WITH NEW ELECTRIC BOOST
Slide33 : BREAZE Solar Hot Water Initiative 3. REPLACE CURRENT ELEC. WITH NEW ELECTRIC BOOST PROS
Getting tank purpose built for solar
Good if going to get very large pv array to offset CONS
Don’t get rebate, only get RECS
Initial purchase cost more expensive
Don’t re-use old tank COST (22 evac tube - indicative only – no installation)
$3560 – (15% disc - $534) – (RECS ~ $400) = ~ $2626
Slide34 : BREAZE Solar Hot Water Initiative 4. PRE-HEAT CURRENT GAS BOOST
Slide35 : BREAZE Solar Hot Water Initiative 4. PRE-HEAT CURRENT GAS BOOST PROS
Cheaper in short term (no instant. boost cost)
Get to re-use old tank and prolong its life (thermal shock)
CONS
Rebate not as generous and don’t qualify for RECS
Tank not purpose built and ‘3 yr rule’
Not maximum emissions and running costs savings
COST (22 evac tube - indicative only – no installation)
$3,560 – (15% disc $534) – (rebate $800) = $2226.60
Slide36 : BREAZE Solar Hot Water Initiative 5. REPLACE CURRENT WITH INSTANTANEOUS GAS BOOST
(probably would have tank on ground, not on roof)
Slide37 : BREAZE Solar Hot Water Initiative 5. REPLACE CURRENT WITH INSTANTANEOUS GAS BOOST PROS
Lowest emissions and running costs of all options
Qualify for rebate and RECS
$1000 Instantaneous unit effectively costs $350
Getting purpose built, most efficient tank CONS
More expensive than pre-heating
Don’t get to re-use old tank
COST (22 evac tube - indicative only – no installation)
$5,071 – (15% disc $760) – (rebate $1,350) –
(RECS ~$520) = ~$2441.05
(exact system equivalent for electric costs $3791 – dammit!)
Slide38 : BREAZE Solar Hot Water Initiative Why should I retire my HWS prematurely?
(the issue of ‘waste’)
Can still re-use (retro/preheat) or recycle. If not
Prior qn – where was it (always) going to go
1. Landfill? (1 answer – don’t have hot water!)
Non-landfill? – could retain tank as grey water collector, bbq, garden bed (‘waste’ issue disappears)
This explains why our system must be robust and long lasting
Slide39 : BREAZE Solar Hot Water Initiative What about ‘wasting’ the embodied energy by retiring current system prematurely?
Embodied energy? Energy from ore to roof
This energy ‘doesn’t go away’ just because system is dead and now in landfill - holding on to current system for, say, 5 years, will still not solve this.
Slide40 : BREAZE Solar Hot Water Initiative Retaining vs Ditching
If current (non green power elec) system spews out 38 tonnes of gg over the next 5 years (as you wait for ‘death’), then it’s much worse to keep than ditch. It would also take 29 MW to run over 5 years
SHWS ‘makes back’ energy (4 MW of solar gain pa – insts. gas = 1.3years/ elec = 2.3 years)
Current system ‘makes back’ no energy.
Stock market cliché – “Time in, not timing”
Early adoption allows “make back” of old system’s “wasted” embodied energy, starts reducing emissions immediately and starts to ‘pay back’ earlier because of running costs
Slide41 : BREAZE Solar Hot Water Initiative Lastly.. What about travel miles from overseas…?
Alan Pears (RMIT Energy efficiency guru) says..
If you're concerned about transport, international shipping is about 0.005 kg CO2/tonne-km. Lets say a solar HWS unit weighs 200 kg and is transported 8,000 km. Then 0.2 x 0.005 x 8000 = 8 kg of CO2. I would double this to allow for the weight of the container, but however you do it this is not a major issue. To be honest, the trucking energy issue is often more important. The ghgs/t-km for semi-trailers are 0.062 kg/t-km, and for rigid trucks, 0.146. These are averages, so a fully load truck would be better - but then there is the return trip....
If you truck a solar HWS 300 km on a rigid truck, the ghgs are 43 kg CO2, much more than the shipping. So railing the equipment saves a fair bit (it's a third or less of the ghgs from a semi-trailer).
I think what you people are doing is great, so if I can help, I will do what I can.
Slide42 : BREAZE Solar Hot Water Initiative QUESTIONNAIRE
Fill out at home
Send back in ‘BREAZE’ addressed envelope
Wait for news of next meeting
THANKS FOR THE LOAN OF YOUR BRAINS. YOU CAN HAVE THEM BACK NOW…
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