Dec. 1

Topic: Photovoltaic systems load calculations. component selection
Powerpoint on PV System Design

Load Calculations spreadsheet:
Load calculations.pdf

by page in .jpg
Load analysis page 38
Load analysis page 39
Load analysis page 40
Load chart page 41
Load analysis page 42
Load analysis page 43
Load analysis page 44

Blank load chart for MAC (excel worksheet)
Blank load chart for PC (excel worksheet)

Homework: Prepare for final design review

Instructions for Final Design Review: Dec 8, 2003
Prepare an oral presentation of your final design. You can use the solar decathlon chart as a guide if you want: See http://www.uvm.edu/~gflomenh/CDAE170/Nov17.html

PASSIVE DESIGN (Same as before, but improved)
1) Present Overall construction technique and Green materials used. List special materials like low-e windows.
2) Drawings
Front elevation
Rear elevation
Side elevations (East and West sides)
Floor plan (usually shown as a top view)
Isometric or oblique view of exterior, which means from the corner so you can see the roof and two sides.
Please include outside dimensions.
Optional: Perspective artistic rendering
Please use a ruler to draw straight lines or CAD.
3) % south window area. (Area of windows/floor square footage) Other window areas optional
4) Area of direct floor mass, indirect floor mass, indirect wall mass, or other thermal mass (water, phase change salts, etc)
5) Include shading strategy for summer, which most left out of the preliminary design
6) Solar fraction if you completed the energy calculations. Overall energy performance.
7) Material cost per square foot if you have done it. (Total cost divided by square footage of living space)

HOT WATER SYSTEM
Describe system used and capacity, brand names, and cost. Call contractor if necessary for quote. See http://www.state.vt.us/psd/ee/solar.htm

PV SYSTEM
Describe overall system loads (from load calculations): average KWH/day, peak KW, (optional surge)
Describe system strategy: 12V, Off the grid inverter, grid inter-tie, or grid inter-tie with battery backup.
Describe system components:
Panels
Charge controller
Inverter
Batteries if you have them
Gauges (amp-hour meters, etc)
Tracker or other options

Total cost

Inverter Size: Peak KW determines the inverter size. Keep in mind you will never run everything at once. Use a good guess, and often it comes down to what you can afford.

PV Panels: Average KWH/day = PV panel array size x hours/day of sunlight (Use 4 hrs.)
or Average KWH/day / 4 = PV array size
example:
10KWH/day /4hrs = 2.5KW
2.5 KW of PV panels would be 25 100watt panels. (about $12,500)

Batteries: AVE KWH/day x days of storage = size of battery bank
10KWH/day x 3days of storage = 30KWH storage needed
Example: using 12V 105AH batteries = 1260 WH or 1.26KWH
30/1.26 = 24 batteries
or 30KWH = 30,000 WH
30,000WH/12V = 2500amp-hours
2500/105AH = 24 batteries

After doing this you can see the benefit of reducing your needs. Electric driers aren't recommended unless you have stock in electric utility.
Maura O'Dea, Erik Hoekstra, Hilton Dier, and possibly Chuck Reiss will be there.
Thank you for your diligent efforts, and I look forward to some great presentations!