Solar PV Today Key Things to Think About for Interested NOCA Homeowners

Transcription

1 Solar PV Today Key Things to Think About for Interested NOCA Homeowners Presented by: Scot Merriam and Ken Romanyshyn, ESVI volunteer technical team For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 1

2 Who Are We? ESVI was formed in 2002; We are a non-profit organization promoting energy efficiency and distributed clean energy generation; We provide free, independent information to VI home owners, businesses and local governments; ESVI relies on membership subscriptions to support our volunteer activities For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 2

3 First Things First! Before investing in your own home clean energy generation system, reduce the energy you consume! Energy efficiency measures typically provide: A shorter payback time than clean energy generation systems such as solar PV; Home energy resiliency and increased comfort Reduced energy consumption reduces the required size of your clean energy generation system, which minimizes system cost For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 3

4 What Does Solar PV Look Like? Grid-Tie System (least costly) Diagram source: wwwviridianenergy.ca For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 4

5 What Does Solar PV Look Like? Off-Grid System (most costly) Diagram source: wwwviridianenergy.ca For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 5

6 Why Go Solar PV? Reduce long term energy cost; Energy independence: For the homeowner; For Vancouver Island Reduce environmental impacts: Transmission line footprints Increased home equity: Recovered if sold or passed on to estate For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 6

7 BC Hydro vs. Solar PV CPI Actual BCH increase CPI Actual BCH increase What BCH Rep Told City of Nanaimo To Expect Solar PV assumptions: South facing 4 kw grid tie on 34 deg. sloped roof with max. 5% shading; structural review & maintenance $ allowances included. LCOE = levelized cost of electricity over 25 years (solar PV system lifetime is expected to be 25 to 30 years so LCOE can be lower) For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 7

8 Is Solar A Good Fit For You? If sloped, does your roof face south, southeast or southwest? Southern exposure is required Is your roof new and in good condition? Solar PV systems have year lifetime so best not to install on old roof Does your roof have the structural capacity? Get it checked by a structural engineer If no to the above, do you have a south facing yard where modules can be ground mounted? For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 8

9 Module Orientation It is still generally important to orient solar PV modules facing south, with degree of tilt equal to latitude +/- HOWEVER: Due to the drop in cost of solar PV modules, it may be more cost effective for horizontal roof situations to mount modules coplanar (flat) than spend $ on extra racking to tilt modules; Can even place modules on roof tilted a few degrees to north For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 9

10 Module Orientation Seasonal Changes For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 10

11 Roof Structural Capacity Performing a design review of the proposed solar PV supporting structure(s) is often overlooked by vendors; While the distributed load of coplanar rack mounted and anchored solar PV modules and cabling is low (up to about 14.5 kg/m 2 or 3 lb/ft 2 ), the point loading from rack to roof anchors can be high; Older rafter supported roofs have more issues with point loading than modern truss supported roofs; Rack mounted and ballasted solar PV systems add even more weight to the supporting structure For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 11

12 Module Mounting Anchor = point load Ballast weights Rack mounted and anchored (sloped roof shown) Rack mounted and ballasted (horizontal roof shown) For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 12

13 Near Shading While solar PV shading losses are often overlooked in general, it is the near shading that can have the greatest impact on annual electricity generation; The near shading effect of local features such as chimneys, roof peaks/gables, building perimeter trees and neighboring buildings must be considered in system layout and design For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 13

14 Near Shading Examples For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 14

15 Shade Mitigation Sites without any shading can be hard to find. If your site has partial shading, consider the following design features: Use solar PV modules with a minimum of 3 integral diodes OR integral DC optimization (new tech); Lay out (wire) solar PV modules in parallel strings; If cost effective, use (a) microinverters or (b) external DC optimizers with string inverters. These module level power electronics (MLPE) provide maximum power point tracking to optimize power output under partially shaded conditions For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 15

16 Theft Solar PV equipment located on low roofs or in high crime areas can be secured with theftproof hardware to avoid loss; Fencing to limit access can also deter theft; Large solar PV systems can be protected by monitored security cameras For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 16

17 Batteries You don t need costly batteries to benefit from solar PV electricity; Homes and buildings connected to most electrical utilities in BC can install a grid-tie system and become a net metering customer, where the utility becomes the customer s battery; Batteries are only required for off-grid applications or where the electrical grid is unreliable cost can be 50% more than grid-tie For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 17

18 System Sizing Generating more solar PV electricity than you use is no longer acceptable under BC Hydro s Net Metering Program; To ensure your solar PV system pays for itself in the shortest time period, we recommend that residential, grid-tied solar PV systems should be sized to cover ONLY the most expensive (BCH Step 2) power consumption For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 18

19 Typical Home Solar PV System Size and Cost Capacity: 4 kw (15) 1m x 1.6m solar PV modules Capital cost: $1,500 +/- for structural engineering check; $12,000 +/- solar PV design, supply, install Cost of electrical permit included in above Currently BC Hydro Net Metering Program is free (but requires Smart Meter) Maint. cost: $80/yr +/- averaged over life For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 19

20 Typical Nanaimo Home Solar PV Annual Generation South facing, 34 deg. tilted solar PV modules with maximum 5% shading will produce about 1,081 kwh/year/kwp*: For 4 kw system, this yields 4,324 kwh/year Horizontal solar PV modules with maximum 5% shading will produce about 923 kwh/year/kwp*: For 4 kw system, this yields 3,692 kwh/year Average RDN home consumes 13,560 kwh/year * From NRCan For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 20

21 Requesting Quotes Requesting quotes from solar PV vendors can be mind boggling for the average homeowner and it is common for vendors to propose different systems and features; To ensure you get a quality system, prepare a Request for Proposals document outlining your annual electricity consumption and detailing what you want; Use of a third party solar PV specification, such as ESVI s Small Solar PV Installation Specification (free to members), can be useful in communicating technical requirements to vendors For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 21

22 Specifications For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 22

23 How Do I Acquire My Solar PV System? Q: Can you afford to pay for your solar PV system in full? A: If yes, then go ahead and purchase it; Q: Can you afford to cover the loan payments for your solar PV system? A: If yes, then take out a loan and purchase it; Q: If I can t pay for my solar PV system in full or afford loan payments, are there other options? A: Yes, consider a solar cooperative such as For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 23

24 Thank You For Your Attention! Questions? For NOCA October 15, SEVENTH STREET, NANAIMO, BC, V9R 1E3 24