powered by the sun
TRANSCRIPT
POWERED BY THE SUNAlex Moundalexis
@technmsg
Slides: github.com/technmsg/sun-powered
CC BY 4.0
WHY ME?18 months w/ solar panels
practical knowledge
computery guy by training and trade
WHY PEOPLE CHOOSE SOLAR?reduce dependency on non-renewables
reduce utility bills
insulate against future energy costs
increase home resale value
cool factor
SOLAR PV 101
RESIDENTIAL PV SYSTEM
0. SUNLIGHT
the sun delivers more energy to Earth in one hour thanhumanity consumes over the course of a year
-- MIT Technology Review
1. SOLAR PV MODULES
Photovoltaics is the direct conversion of light intoelectricity at the atomic level.
-- NASA
remember solar calculators?
ever notice that old ones get flaky?
Photons strike and ionize semiconductor material on thesolar panel, causing outer electrons to break free of their
atomic bonds. -- Solar Energy Industries Association
solar panel output degrade over time
most manufacturers warrant ~80% of rated power a�er 25 years
2. INVERTER
converts direct current (DC) into alternating current (AC)
(apologies to Nikola Tesla)
2A. PRODUCTION METER
measures what the system produces
3. FUSEBOX
backfeeding
bus bars don't care about the source of power
4. BATTERY (OPTIONAL)
expensive
heavy
maintenance
5. METER
by default, meters measure absolute usage
net metering
6. GRID
ACQUISITION
PURCHASEyou own it
all the incentives
cash up front / special loans
LEASE / PPAvendor-owned
buy power per-kWh
typically zero down
no incentives
COMMUNITY SOLARshared roo�ops & spaces
shared costs
shared incentives
co-op style
PICKING A VENDORshop around
savings calculations (kWh)
3rd party contractors
reputation
local presence
PAPERWORK
INSPECTIONroof: dimensions, orientation, gotchas
attic: truss spacing
electrical: panel
SYSTEM DESIGNCAD drawing
power output report: accounts for dimensions, orientation, roof pitch, shade,time of year
INTERCONNECTnotifies utility of intent to generate power
proper billing
safety for utility workers
HOA APPROVALSsolar easements and rights laws
(tedious)
SREC REGISTRATIONSolar Renewable Energy Credit
1 MW = 1 credit
commodity market
typically sold via aggregator to utilities
EXAMPLE SYSTEM #116 SunPower panels
SunPower inverter
3.92 kW
purchase
17,000 USD
EXAMPLE SYSTEM #224 Yingli panels
SolarEdge inverter
6.63 kW
20 year PPA @ 11.3¢/kWh
zero down
EXAMPLE SYSTEM #320 unknown panels
unknown inverter
6.25 kW
20 year PPA @ 6.1¢/kWh
7300 USD pre-paid in full
INSTALLATION DAY
BEFORE
DURING
AFTER
ACTIVATION
waiting...
for a County inspector to check structure & electrical
for the power company to install the net meter
(anticlimactic)
BREAK?
IMPACT
DAILYwith net metering, usage unchanged
most days production > usage
w/o net metering, migrate demanding tasks to daytime
Energy Produced on 2 May 2016
MONTHLYproduction varies by season
no maintenance required
Energy Products in 2015
LONG TERM12 months in...
85% of my electrical needs
50% expenses recouped
payoff expected in 5-6 years
MONITORING
Dashboard
GAMIFICATIONinevitable, given data
measure everything
minimize usage
DAILY USAGE
BIG USES2 kWh - fridge
2 kWh - always-only Internet**** fiber ONT, router, UPS, two wireless routers, Chromecast, VOiP bridge, VOiP handsets, core switch
LIGHTINGlargely overlooked
inefficient incandescent
3-way bulb > entertainment center
ELECTRONICSmost modern electronics are wildly efficient
1 kWh - 8 hrs WFH: laptop, monitor, speakers
¼ kWh - stream a movie on home theater
STANDBY CONSUMPTION
INKJET PRINTER1.4W standby
0.1W powered off
DELL FLAT-PANEL35-45W in operation
3.7W standby
3.6W powered off
DOWNSIZING
HOME SERVERDell PowerEdge SC 440
100W = 72 kWh/month = $9.36
vs
Raspberry Pi B+
1.6W = 1.5 kWh/month = 20¢
(ENERGY) PRODUCTION DATAREST API
web scraping
to automate browser activitySelenium
ENPHASE
The allows mobile apps, buildingmanagement tools and other so�ware applications to
access and use system performance data. --
Enlighten API
Enphase Support
SOLARCITY
The PowerGuide API is a RESTful service that can beinvoked from any HTTP client, and allows you to query
PowerGuide Data. -- PowerGuide API documentation
SUNPOWER
The API was developed for our flex applications and thereare no plans to make it available to 3rd party developers.
-- @sunpower
CSVInterval Start Date,Energy (kWh) 2016-05-14T05:00:00,0 2016-05-14T06:00:00,0.040 2016-05-14T07:00:00,0.160 2016-05-14T08:00:00,0.270 2016-05-14T09:00:00,0.390 2016-05-14T10:00:00,0.930 2016-05-14T11:00:00,1.440 2016-05-14T12:00:00,1.530 2016-05-14T13:00:00,2.780 2016-05-14T14:00:00,0.810
SPECIAL THANKSFreedom Solar Power
SunPower
(show and tell goodies)
MORE WORDSBlog: Going Solar
bit.ly/v2-solar
Get solar (via SunPower)
bit.ly/get-solar
Slides
github.com/technmsg/sun-powered
