POWERED BY THE SUN
Alex 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 than
humanity consumes over the course of a year
-- MIT Technology Review
1. SOLAR PV MODULES
Photovoltaics is the direct conversion of light into
electricity at the atomic level.
-- NASA
remember solar calculators?
ever notice that old ones get flaky?
Photons strike and ionize semiconductor material on the
solar 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
PURCHASE
you own it
all the incentives
cash up front / special loans
LEASE / PPA
vendor-owned
buy power per-kWh
typically zero down
no incentives
COMMUNITY SOLAR
shared roo ops & spaces
shared costs
shared incentives
co-op style
PICKING A VENDOR
shop around
savings calculations (kWh)
3rd party contractors
reputation
local presence
PAPERWORK
INSPECTION
roof: dimensions, orientation, gotchas
attic: truss spacing
electrical: panel
SYSTEM DESIGN
CAD drawing
power output report: accounts for dimensions, orientation, roof pitch, shade,
time of year
INTERCONNECT
notifies utility of intent to generate power
proper billing
safety for utility workers
INCENTIVES
federal / state / local
grants
tax credits
www.dsireusa.org
HOA APPROVALS
solar easements and rights laws
(tedious)
SREC REGISTRATION
Solar Renewable Energy Credit
1 MW = 1 credit
commodity market
typically sold via aggregator to utilities
EXAMPLE SYSTEM #1
16 SunPower panels
SunPower inverter
3.92 kW
purchase
17,000 USD
EXAMPLE SYSTEM #2
24 Yingli panels
SolarEdge inverter
6.63 kW
20 year PPA @ 11.3¢/kWh
zero down
EXAMPLE SYSTEM #3
20 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
DAILY
with net metering, usage unchanged
most days production > usage
w/o net metering, migrate demanding tasks to daytime
Energy Produced on 2 May 2016
MONTHLY
production varies by season
no maintenance required
Energy Products in 2015
LONG TERM
12 months in...
85% of my electrical needs
50% expenses recouped
payoff expected in 5-6 years
MONITORING
Dashboard
GAMIFICATION
inevitable, given data
measure everything
minimize usage
DAILY USAGE
BIG USES
2 kWh - fridge
2 kWh - always-only Internet**
** fiber ONT, router, UPS, two wireless routers, Chromecast, VOiP bridge, VOiP handsets, core switch
LIGHTING
largely overlooked
inefficient incandescent
3-way bulb > entertainment center
ELECTRONICS
most modern electronics are wildly efficient
1 kWh - 8 hrs WFH: laptop, monitor, speakers
¼ kWh - stream a movie on home theater
STANDBY CONSUMPTION
INKJET PRINTER
1.4W standby
0.1W powered off
DELL FLAT-PANEL
35-45W in operation
3.7W standby
3.6W powered off
DOWNSIZING
HOME SERVER
Dell PowerEdge SC 440
100W = 72 kWh/month = $9.36
vs
Raspberry Pi B+
1.6W = 1.5 kWh/month = 20¢
(ENERGY) PRODUCTION DATA
REST API
web scraping
to automate browser activitySelenium
ENPHASE
The allows mobile apps, building
management 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 be
invoked from any HTTP client, and allows you to query
PowerGuide Data.
-- PowerGuide API documentation
SUNPOWER
The API was developed for our flex applications and there
are no plans to make it available to 3rd party developers.
-- @sunpower
CSV
Interval 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 THANKS
Freedom Solar Power
SunPower
(show and tell goodies)
MORE WORDS
Blog: Going Solar
bit.ly/v2-solar
Get solar (via SunPower)
bit.ly/get-solar
Slides
github.com/technmsg/sun-powered
THANKS
Alex Moundalexis
@technmsg

Powered by the Sun