Energy module notes

Energy modules-2016-2017

Module 1: measurement-volts, ohms, AC and DC

VOM meter: 2 lead VOM, e.g. Fluke Model 114

Measure ohms short and open

Measure ohms across chest (can calculate fatal voltage here if current is known)

Measure ohms around circle of students, break circuit (circuit concept here: need two wires)

Define "circuit"

Measure voltage across chest-why does it vary? (EKG concept, can extend to differential EKG)

Measure DC voltage of small batteries (learn what symbols for DC and AC voltage are on the meter)

Measure AC voltage at outlet (caution here)

Explain why dry hands are better, cross body shocks, grounding

Measure resistance from hands to ground

Electrical safety unit…

Module 2: power measurement

Kill-a-Watt unit

Ohmic loads: tea maker, coffee maker (make sure water is cool)

P=VI

P = I2R

Measure voltage at outlet

Measure resistance of ohmic load with VOM

Predict power used, current

Measure power, current (ohmic load)

Power measured/power calculated = ?

Repeat with vacuum cleaner or other motor device

Recalculate power calculated vs. measured

P = VI again, vs. power measured

Try the P.F. button

Module 3: lighting evaluation

Light bulb analysis:

Incandescent bulb: measure R with VOM, measure power with KaW unit

CFL: repeat

LED: repeat

Next measure light output for each, compare with power used (measured with KaW unit)

Cost to run:

Calculate cost to use each bulb for 1 hour, define kWh.

Calculate cost to run tea maker for 1 hour, define kWh.

Calculate savings between LED, CFL and incandescent bulb, per day, week, month, year, over lifetime

Define ROI and TCO

Module 4: Renewable energy

ROI and TCO

PV, Wind and Solar thermal

ROI is time to pay off device (in days, months or years)

TCO is total cost of ownership (should be negative)

Data from websites or hands-on if available

Module 5: power factor

Energy testing

Test power used by hot water heaters, chargers, vacuum cleaners, toaster, microwave, lights

Make sure to record PF as well (power factor) what is this?

Module 6: energy profiles:

Energy profiles: graphical analysis

Using elab2.hpa.edu, identify samples by:

1. magnitude
2. time of day
3. shape

Module 7: Efficiency evaluation

PV panel

Measure incident solar radiation (or from weather service) in W/m2

Measure output of PV panel, using ohmic load (resistor or tea maker), current, voltage

Calculate % efficiency

Solar Thermal Panel

Solar thermal same incident solar, measure temp in and out for solar panel, and time to fill 1 liter container (flux). three cases: slow, medium, fast

Use mc∆t to calculate calories captured/harvested, 4.18j = 1 calorie, j/s = Watts

IR photo in three cases: slow, medium, fast

Wind turbine

Difficult with varying wind, you may be able to hold small turbines while driving a truck (this is how some are actually evaluated)

Area of turbine is needed, and wind speed, altitude (air density) as well

Look up Betz coefficient, 0.39 is max (why?)

May be done using data from manufacturers

Module 8: Energy audits

Residential energy audits

TED units (theenergydetective.com)

Installed at houses, classrooms

Measures predicted billing, uses, trends

Excellent for articulating with commercial energy audits

Module 9: CT measurement

Control by web units, using current transformers

CBW analog units process 8 analog 0-5Vdc inputs to web interface with logging

CTs are Hawkeye 922 units (0-5 Vdc output), with 30,60 and 120 Ampere rating

Larger ones as well

Assume PF = 1.00, calculate Watts from P = VI (assume voltage constant, but measure accurately to calibrate)

Module 10: elab2.hpa.edu server

Energy Lab server

elab2.hpa.edu

Telemetry of campus or remote locations

Can interface with CBW units globally, as long as they have access to internet

Used in "energy hunts" finding lights or loads hidden around buildings

Module 11: EMC server

Templates

Dashboards

Widgets

Module 12: Energy Hunt

Elab hunt:

Using elab2.hpa.edu, see if you can see the energy used at certain outlets, on/off

Module 13: IR analysis

Hot water heaters

plumbing

pool pump

solar panels

Module 14: Superthermos

Q/t=kA/d

exponential decay

R = 1/k

Module 15: Energy to make cookies

recipe

oven

ohmic or PF?

Module 16: dorm hot water

System comparisons

Sola hart vs. panel/tank system

Module 17: PV comparison

Elab three panel systems

SMA vs. Enphase

Module 18: Energy storage

ST vs. DC battery storage

PSH analysis

flywheel analysis

Module 19: Sustainable post-contact Hawaii Island

SEWTHA: GB vs. Hawaii Island

Module 20: HPA grand plan: Net neutrality

We have three ways we can claim neutrality:

1. Net energy neutral: We export the same amount of energy around noon that we use overnight, so as far as the HELCO grid is concerned, we have a net zero energy profile. We still pay for what we use at night, though)
2. Net money neutral: We capture any excess energy during the noon hours when the HELCO meter would be spinning backwards, and use this at night from our batteries or other storage)
3. Net carbon neural: We measure all carbon used on campus, including transportation, heating and other carbon impacts and offset with energy produced via solar thermal, PV, wind or other means (not nuclear, don’t worry). This is the most current global metric used, and relates well to our sustainability misssion.

Each has certain PR and moral aspects, but we are in a uniquely resource dependent environment, so any of these would be an excellent case study for student research, internal and external relations, or grant opportunities.

Module 21: lighting eval

Tennis, Gym and library all have new LED lighting. Evaluate, creating a coverage map of each, using LUX as the unit

Module 22: e2 videos

Harvesting the wind (see APES for questions)

Energy for a developing world (ditto)

hydrogen power-Iceland, PWW

biofuels-Brazil

Module 23: Starbucks profit

Boil water in tea makers

Calculate energy used for volume

Research cost of Sbux coffee/size in ml

Calculate profit per cup (based on energy)

Estimate daily profit for sbux

(exceptions: espresso, latte, frappaccino)

Module 24: faculty cottages

Open each closet

before and after IR photos

visual thermometer

greybox setting

Steca monitor

===============energy primer================

Energy primer

Energy and power units:

kW means kiloWatt, kilo = 1000 Watt named after a person, so capitalized

1000 Watts = 1 kW (note spelling)

kW is a rate, like miles per hour or gallons per minute

To get total energy (or miles or gallons) we multiply by time:

1000 Watts for one hour = 1 kWh (“one kiloWatt hour”)

Example: a 1000 Watt hot water maker is on for one hour

1000 W = 1 kW times 1 hour = 1 kWh

KVA is another unit similar to kW, but it includes what is called the power factor.

For simple things like hot water makers or toasters, PF (power factor) = 1.00, meaning 100% of the electrical energy goes to work.

Motors, compressors, refrigerators, computers and pumps can have power factors as low as 50%, meaning if you think the device is using 1000W, you are really paying for 2000W.

HELCO charges us a premium if our campus total PF is less than 90%

HELCO charges us about $0.40 for every KVA, so if you have an energy number, you can round to about half of this number to convert to dollars (neat tip).

Note on units: Watts, Volts, Amps (Amperes) are all capitalized. Don’t capitalize meters, hours or gallons.

Lighting:

We are in the 4th generation of lights in this country.

~1850 incandescent lights (Edison and his gang)

Most energy goes to heat, not efficient, simple to operate, PF 1.00

~1950 Fluorescent lights (note spelling: flUOrescent, like FlUOrine)

More efficient, contain mercury, need a transformer (hot, noisy)

Related: mercury vapor (white) and sodium vapor (yellow) lamps, also known as metal halide lamps, often found in streetlights, gyms, tennis centers. PF is about 80%.

All of these create an electrical arc through a vapor of metal (even fluorescent bulbs, which contain mercury and a phosphorus inner coating to transform the harsh mercury light into visible light)

~2000 Compact Fluorescent bulbs (CFL)

Similar to traditional long or circular bulbs, but able to screw into 1850 era light sockets (yes, they are that old).

Contain mercury and phosphorus, 3-5 year lifespan, PF ~80%

~2010 Light Emitting Diodes (LED)

Very efficient, can be many colors, little heat, long lifespan, PF close to 95%, uses about 65% less energy than traditional bulbs, relatively expensive, but long lifespan makes for excellent ROI and TCO (return on investment, total cost of ownership).

Conservation:

Every dollar spent on conservation is worth about $8 in new energy sources.

Monitoring is key, to determine energy flows, leaks and so on

This can be electrical metering, infrared cameras, flow meters, propane meters, water meters, temperature sensors and so on.

Key targets are refrigeration, water pumps (e.g. pool), lighting, water heating and timing-when these resources are used relative to energy harvesting.

Especially important at night, when PV and solar thermal systems are dependent on storage

Solar thermal:

Goal: turn solar radiation into hot water

Active systems: Sun—>solar panel—>pump—>tank—> users

Passive systems: Sun —>solar panel/tank —> users (no pump needed, uses convection)

HPA systems are of two types:

Carter dorm has the active system, while Perry-Fiske and cafeteria have passive Solahart systems

Propane is used to finish these systems, making sure that users always have hot water at about 120°F

Hot water is stored in tanks, with about 10-15 kWh energy in each Solahart tank. Each Solahart system costs about $6K installed (panel and tank). To store 10 kWh using batteries would cost $13,000.

Solar thermal panels are about 90% efficient at converting solar radiation into hot water. PV panels are about 15% efficient in converting solar radiation into electrical energy.

Propane is competitive with electrical energy at about $0.25 per kWh equivalent in our hot water heaters.

PV (photovoltaic): light to DC electrical energy

If solar thermal captures solar radiation as heat, PV systems convert this radiation into electrical flow in one direction (direct current, or DC, like batteries). This is convenient for battery storage, but to be used in most homes and businesses, AC (alternating current, 60 Hz) is needed. Inverters are electronic devices that turn DC from PV and/or batteries into AC for use.

Since HPA is on one meter with HELCO, we are essentially a “micro-grid” meaning any electrical energy harvested from PV (or released from batteries) goes to slow down the HELCO meter. Since we do not presently get any credit for energy out, we want to make certain we can store any excess energy on campus for night time use.

Since the sun is brightest at noon, PV engineers use an estimation of a PV array output called “solar hours”, meaning the equivalent amount of energy harvested if noon lasted that many hours.

For example, our PPA (purchase power agreement) array behind the elab produces about 100 kW maximum. This is true at noon, but less so either side of noon, so we use “solar hours” to estimate energy harvest each day. For us, this is about 5.5 solar hours, depending on season:

100 kW x 5.5 solar hours = 550 kWh or about $200 saved each day.

PPA arrangements usually charge us a fraction (about $0.20 per kWh) of the HELCO cost, but we have to pay for what it produces, not what it uses. If we are pushing energy out the door to HELCO using the PPA array, we are in effect paying to give this energy away.

Net zero energy is when we have effectively stopped the HELCO meter, meaning we are producing exactly how much we are using.

We hope to harvest enough to reach net zero around 10AM each day until about 2 PM each afternoon. The extra energy during that time we hope to capture using battery and other storage systems (pumped storage hydro, hot water activation, etc.)

Energy Storage:

Batteries for large scale systems are usually either lead acid batteries dating back to around 1800, or lithium batteries from this century:

~1800 lead acid batteries

lead and sulfuric acid

environmentally nasty

3 year lifespan

shorter if used more

only 40% of capacity is usable

slow discharge and recharge

about $300 for each kWh stored

example: our overnight campus use is about 100 kW for 20 hours or 2000 kWh (or 2 mWh). At $300/kWh this would cost us $600,000 and would last 3-5 years at max capacity, but in actuality it would be 2.5 times this because these batteries cannot be discharged all the way, so $1.5M.

~2010 lithium batteries (LiPO, Lithium iron phosphate, etc.)

used in prius and other cars

lightweight

fast discharge and recharge

20 year lifespan at 80% capacity

greener

expensive ($1300 per kWh)

The same example above would cost more, last longer, and require fewer batteries. It could also discharge faster to maintain our microgrid, and recharge faster when used as backup power for the IT building.

Pumped storage hydro:

Water tanks low on campus have a pump and a generator. When we have extra energy, we pump this water uphill to a similar tank where it is stored for use later on. When needed, the system activates the generator, which provides power for the campus. This is green, cheap, renewable, lasts 50 years or more and can be safely integrated into other water systems (e.g. fire suppression) as needed.

Net neutrality:

We have three ways we can claim neutrality:

1. Net energy neutral: We export the same amount of energy around noon that we use overnight, so as far as the HELCO grid is concerned, we have a net zero energy profile. We still pay for what we use at night, though)
2. Net money neutral: We capture any excess energy during the noon hours when the HELCO meter would be spinning backwards, and use this at night from our batteries or other storage)
3. Net carbon neutral: We measure all carbon used on campus, including transportation, heating and other carbon impacts and offset with energy produced via solar thermal, PV, wind or other means (not nuclear, don’t worry). This is the most current global metric used, and relates well to our sustainability misssion.

Each has certain PR and moral aspects, but we are in a uniquely resource dependent environment, so any of these would be an excellent case study for student research, internal and external relations, or grant opportunities.

dashboard choices

Frida-pool conservation

Taryn-carter ST storage

Andres-IT complex

Annaliese-Art PV

Ella-cafeteria-conservation

Dylan-tennis lighting

Nakoa-PPA array harvesting

Sebastian-PF dorms collection

jacob-GPAC conservation

AnnMarie-wind turbine harvesting

Cerro-PF storage

Austin-student union complex

Amelia-elab solar harvesting

Teah-cafeteria solar thermal/PV

Lyons-carter hot water

PWW

EMC-HPA

offgrid

HVAC

solar ac

wind

pv

solar thermal

conservation

measurement

EMC-residential

microgrid

transportation

storage

hybrid cars

smart buildings

passive solar

nasa

EV energy

cst

tidal

geothermal

notes-

Elab power labels-by room, post-its

weblog: physics questions

Shower equivalent energy used-PF/Carter, savings

Electric vehicles vs. hybrids

Tesla 245 miles per 73.5 kWh, find miles per kWh

http://www.fueleconomy.gov

20# CO2 per gallon of gasoline

1 gallon of gasoline = 33.40 kWh

https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent

Nissan Leaf 25 kWh full charge, find range and PF

electric fuel cost?

HEAT video-climate change

carbon footprint-HPA

Net neutrality: carbon, energy, dollars (3 teams, tokens)

pool pump valves-IR camera

4590 W per tree

65.5 x 41.0 x 1.1 dimension

Energy video

solar panel actual efficiency (W/m2 vs. Watts output) 3 arrays: PPA, trees, IT, elab

turbine actual efficiency (wind speed, area of turbine, KE vs power out)

check cottage tank sensors

ROI/TCO on solar trees

ROI/TCO on union batteries

total campus energy per day

total solar collection per day

total savings per day/month/year

total propane savings per month

storage modes: batteries, lithium, PSH, hot water

weblog: photos of melting lava

info-doodle

5 smart things

solar oven-heat water, compare with electrical water heating, cooking

——

wind power

energy videos: e2

Tesla car integration-big vision

Microgrid

Smart grid