Solar Ready Houses in Cold Climates

Solar Energy Project Development Specialists

Gordon Howell, P.Eng.Edmonton

Phone: +1 780 484 0476E-mail: [email protected]

©1995-2008

Making Your New House Solar Ready

Alternative Energy Trade FairPeace Citizens’ Recycling Society

Peace River2008 November 15, 16

(download this presentation from www.hme.ca/presentations)

Solar Energy Project Development Specialists 2

Alternative Energy Trade Fair Peace Citizens’Recycling Society

Intro: Me! ––

I am a solar system project developer

I am not an equipment supplier

I have no vested interest in any technology

My interest is that you choose wisely– with your eyes wide open– based on the facts and

whether it is right for you or not.

The Earth provides enough to satisfy every man's need, Mohandas Karamchand Gandhi…but not every man's greed. (Mahatma) India



Intro: What the Presentation Does…

Helps you understand how to plan your new home to easily accept a solar heating or a solar power system

Gives you space to ask questions and get answers right away

Solar domestic water heating systemEdmonton



What does “solar ready” mean?

Preparing the house at its planning and construction stage

to easily allow

active solar heating systems or

solar photovoltaic (PV) electricity systems

to be added whenever you are ready for them



Why make your house solar ready?

Allows you to install a solar hot water heater when you are ready

Maximizes the performance of your solar system due to correct solar orientation of the roof

Will save hundreds of dollars when the solar system is installed

Improves the looks of the solar system as all the plumbing or wiring is hidden inside the walls

Increased resale value of your home in being “Solar Ready”



How do you plan for solar energy?

Minimisethe heating and electricity consumption of the house– The cheapest energy option

Maximisesolar energy contribution to the house’s heating and electricity supply



The most expensive way to employ solar…

0%

25%

50%

75%

100%

Conventional Efficient Efficient & Renewable

Conventional Energy Add

expensive solar

energy

Net zero energy home

#2#1 #2

Renewable Energy

Purchased Energy

Inexpensive, reliable energy

efficiency…

#1 #2

Cost: $250k

Where is it?



The least expensive way to employ solar…

0%

25%

50%

75%

100%


Purchased Energy

Conventional Energy

More expensive

solar energy


#3#1 #2

Inexpensiveenergy efficiency

Efficient Efficient & Renewable

#1 #3#2

Cost: $90k to $110k(and decreasing)



The most exciting way to employ solar…

0%

25%

50%

75%

100%


Energy efficiency:

most important, least expensive


#1 More expensive…

yeah, but really exciting

Efficient & Renewable

Renewable Energy

#3#2

ConventionalEnergy

Purchased Energy

Solar energy

#1 #3#2



Three easy steps to become Solar Ready

Making a home Solar Ready can be done in three simple steps:

1. Leave space in the utility room– for the solar storage tank: on the floor beside the

conventional water heater, or– for the inverter and switchgear: on the wall near the breaker

panel.

2. Install a vertical chase or conduit– for the solar water pipes or electric cables from the utility

room to the attic.

3 Ensure that the house has a south-facing roof that



What areas need to be looked at?

1. Minimise the energy consumption of your house

2. Maximise the solar energy production

3. Plan your roof or wall

4. Plan against shading

5. Plan for the looks of the solar array

6. Plan the routing from outdoors to utility room

7. Plan the space in the utility room

8. Costs of becoming solar ready



1. Minimising House Energy Consumption

Drastically reduce your house heating and electricity consumption– The cheapest energy option is to reduce your heating and electricity

consumption by 60% to 70% before adding solar.

Hire a consultant to model the energy consumption of your home using the Natural Resources Canada’s HOT2000 home energy software

Use HOT2000’s results to plan:– Electrical appliances and lighting– Size of house, orientation– Insulation levels, window types– Airtightness levels, ventilation system– Passive solar heating – window areas, orientation and house thermal mass– Optimised size and type of heating system (if it is still needed)



2. Maximising Solar Energy Production

The size of your solar energy system depends on:How much of your electricity and your heat you want to produce from the sun

This number is a target. – You don't have to have all your electricity and heat provided by solar.– Solar systems can be modular so that you can start small and add.

6 PV modules 18 PV modules16 PV modules2 collectors

South of the UofA In Calgary Eric Steeden’s house Peter Bull’s house



2. Maximising Solar – Where do you live?

Size of your solar energy system depends on:

How much energy is in the sunlightwhere you are located?

Use RETScreen™ to give you an idea of how much solar it will take to supply your house

RETScreen spreadsheet analysis software available free from Natural Resources Canada

www.retscreen.net



3. Planning the roof or wall

Look at:

a) Roof tilt angle

b) Roof orientation angle

c) Amount of space available

d) Intrusions into the roof or wall space

e) Strength of roof or wall



-30%

-25%

-20%

-15%

-10%

-5%

0%0 10 20 30 40 50 60 70 80 90

Peace River

% of energy from optimum annual tilt angle

Horizontal Vertical

4.5

3.3

3.8

sun-hours/day

= kWh/m2/day

3a) Optimum Annual Roof Tilt Angle

Snow cover?Reflection from snow fields?

If well planned then solar array mounting costs can be reduced.

The maximum annual solar energy production occurs at around a 51° tilt.If your goal is to maximise this, your tilt angle can be from 20° to 80° and still be within 10% of the maximum.



-80%

-70%

-60%

-50%

-40%

-30%

-20%

-10%

0%0 10 20 30 40 50 60 70 80 90

% of energy from optimum winter tilt angle

Horizontal Vertical

1.0

3a) Optimum Winter Roof Tilt Angle

Snow cover?Reflection from snow fields?

Peace River

3.65

Sun-hours/day

3.2 3.61

The maximum winter solar energy production occurs at an 81° tilt.If your goal is to optimise this, your tilt angle can be from 52° to 90° and still be within 10% of the maximum.



-35%

-30%

-25%

-20%

-15%

-10%

-5%

0%230 220 210 200 190 180 170 160 150 140 130

% of energy from optimum winter orientation angle

Peace River

SW South SESSESSW

3b) Optimum Winter Orientation Angle

Choose a south facing roof if at all possible, not an east-west facing roof

3.6

Sun-hours/day

3.2 3.2

If the goal is to optimise the wintertime solar energy production, you can orient the roof or wall 28° either side of south and still be within 10% of the maximum, which is at due south.



3c) Amount of area – solar heating

Solar heating system:

– 2 flat-plate collectors or 30 evacuated tubes require a 3 x 3 metre (10’ x 10’) clear roof space

– This is the size for a typical solar domestic water heating system

– Collector size:Flat plate collectors are typically 1200 mm x 2400 mm (4’ x 8’) each

Evacuated tubes are typically 1800 mm to 2400 mm long (6’ to 8’) and come inbanks of 30 that are 900 mm to 1200 mm wide (3’ to 4’)



Photo Credit: Trimline Design Centre

Glazed Flat Plate Collectors

Many flat plate solar collectors are around a 4’ x 8’ size, with some differences



3c) Amount of area – solar PV system

Solar electricity (photovoltaic or PV) system:

– Takes up 6 to 10 m2 (65 to 110 ft2) for each kW of generating capacity, depending on PV module efficiency

– Typically, a house could have anywhere from a 1 kW to a 10 kW system on it – 60 to 100 m2 (650 to 1000 ft2)

– PV module size:Widely varying sizes and dimensions

600 mm to 1200 mm wide (2’ to 4’) x 1200 to 1800 mm long (4’ to 6’) depending on manufacturer and technology



3d) Roof or wall intrusions?

Too many obstructions fill up

the roof space

Is your roof free from obstructions? – Roof vents– Plumbing stacks– Chimneys– Dormers– Skylights– Satellite dishes

Is your wall free from obstructions? – Windows– Doors– Exhaust or intake vents– Water taps– Gas or electricity meter

These take up valuable clear roof space and can complicate a solar installation significantly or even prevent it from happening.



Mounted on a metal roof

House in Edmonton


Alternative Energy Trade Fair Peace Citizens’Recycling SocietyMounted on a rack

above the roof line

House in Edmonton



Mounted on a wall

Airdrie Environmental Recycling Centre



What to do if your roof or wall just won’t work?

Consider something other than the roof or wall!– Mounting on the ground, pad or pole– Window shading– Garage roof– Yard feature – garden trellis

Saskatoon Advanced House

Eric Steeden’s house and PV system



Garage mount…

Photo Credit: Trimline Design Centre

House in Edmonton



Ground or pole mount…

Talk to a solar supplier about the additional costs involved



Collectors – mounted horizontally on roof rack

Tim Belec’s house, Pigeon Lake



3e) Strength of the roof or wallIf solar array is tilted up off the roof then you must consider:

– Wind loading– Changing patterns and buildup of snow– See a structural engineer to check this

Increase in weight on roof– Needs to be checked – usually much smaller than the trusses’

live load design– Speak with your truss manufacturer

Solar heating collectors and mounting rack– Can add 24 kg/m2 (5 lb/ft2)

Solar PV modules– Can add 15 kg/m2 (3 lb/ft2)



4. Plan against shadingSolar heating system

– Shading reduces the heat production by the amount of shaded area– 10% shading means 10% less heating

Solar PV system– Direct shading can be catastrophic!

Small amounts can turn off the whole PV array (depending on how it is electrically configured)If not designed well, it can cause PV cells to become electricity users and turn very hot

How clear are your solar sightlines from shading?Relocate the solar arrays away from all close-by direct shading:

– Chimneys– Dormers– Trees– Buildings



4. Plan for landscaping

Where are your coniferous and deciduous trees?– Deciduous trees can let in 80% of the light in the winter.

To what height will your trees grow?

South of the UofA

Kerry Wood Nature Centre

House in Edmonton



5. Plan for how the solar arrays look…Make it stand out to attract interest?

Integrate it into the roof to become unseen?

How much curb appeal do you want?

How will it affect marketability?

House in Edmonton

Riverdale NetZero energy house in

Edmonton



6. Plan the routing of piping and wiringPlan the route for piping and/or wiring from roof to utility room.Solar heating:

– Minimise the length of the pipe run – max 15 m (50’)– Install a single straight 100 mm (4”) chase or two 50 mm (2”) chases

For the solar water piping and sensor wiringCan be lightweight PVCSeal it at both ends

Solar PV:– Minimise the length of the wire run– Install a 38 mm (1.5”) conduit for the DC PV cable, sealed at both ends

Be careful to seal any roof and wall penetrations.

Consider an attic catwalk from the attic hatch to the location of the solar system



7. Plan the space in the utility room

Solar heating– 1.5 m x 2 m (5’ x 6’) on floor for solar water tank– 1 m x 1 m (3’ x 3’) on wall for controls and pumping package

Solar PV– 1200 x 1200 (4’ x 4’) of wall area with plywood cover – for the

inverter and disconnect switches– Add twice this amount or more if there is a battery bank– If a battery bank is used, it needs

2 to 10 m2 (20 to 100 ft2) of floor area depending on sizeLockable vented compartment



Storage tank (200 to 300 litres)

with heat exchanger inside

Pump controller

Solar circulation pump

Heat Storage Tanks

ThermoDynamics Solar Boiler

Storage tank

Heat exchanger and pump



PV inverter and disconnect switches

Eric Steeden and his inverter and disconnect switches

Kyle Kasawski turning on the Riverdale NetZero PV system



8. Costs of becoming solar ready

Typical prices. Final costs can vary with house size and complexity

Solar domestic water heating– $600 to $900

Solar PV– $400



Want to learn more?

There is a lot of information already available for you.

Solar Energy– Solar Energy Society – Northern Alberta Chapter

(www.solaralberta.ca)

– Canadian Solar Industries Association (www.cansia.ca)“Making your home ready for Solar Water Heating”



Gordon Howell, P.Eng.Gordon Howell, P.Eng.HowellHowell--MayhewMayhew Engineering, Inc.Engineering, Inc.15006 15006 -- 103 Avenue103 Avenue Phone:Phone: +1 780 484 0476+1 780 484 0476Edmonton, AlbertaEdmonton, Alberta T5P 0N8T5P 0N8 EE--mail:mail: [email protected]@hme.ca

©©19951995--2008 Photo credits: Gordon Howell and several others2008 Photo credits: Gordon Howell and several others

…… helping solar meet the helping solar meet the tides of changetides of change

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Solar Ready Houses in Cold Climates