Solar Hot Water Systems North Country Sustainable Energy Fair 2007 Matt Bullwinkel Alternative and Renewable Energy Applications Program SUNY Canton April 28, 2007

Video

Systems PV Panel to Power Pump HelioStat Solar II Kramer Valley CA Power Plant

Jets Stadium NYC “ 1000 of Thermomax tubes..” http://www.thermotechs.com/NY%20Jet%20Stadium.php

“ 1000 of Thermomax tubes..”

Why not solar water heating? Capital cost ($5K vs. $200-$1K for conventional electric or gas heater) System failures Freezing Overheating Leaks Aesthetics Perception: not enough sun/ too cold Finding qualified designers/installers

Capital cost ($5K vs. $200-$1K for conventional electric or gas heater)

System failures

Freezing

Overheating

Leaks

Aesthetics

Perception: not enough sun/ too cold

Finding qualified designers/installers

Why solar water heating? Free Fuel* High Fuel Costs Modest capital cost (vs. PV, wind) Big Bang for Buck: DHW ~30% energy bill Well established: retro fit, “just works” Favorable economics to provide fraction of DHW 60-70% Federal &State Tax credits Renewable *We have a fuel crisis, not an energy crisis, energy always conserved (kinda)

Free Fuel*

High Fuel Costs

Modest capital cost (vs. PV, wind)

Big Bang for Buck: DHW ~30% energy bill

Well established: retro fit, “just works”

Favorable economics to provide fraction of DHW 60-70%

Federal &State Tax credits

Renewable

Too Cold /Not Enough Sun Florida Solar Research Center NC State Solar Center Univ Wiscosin Solar Research ! http://www.fsec.ucf.edu/en/consumer/index.htm

Applications DHW (Domestic Hot Water) Pool Heating Space Heating Cooling Process hot water Electric Power

DHW (Domestic Hot Water)

Pool Heating

Space Heating

Cooling

Process hot water

Electric Power

Outline System Types Solar Resource Operating Principles Background Example Installations Economics Organizations: Promoting Solar, Incentives, Training

System Types

Solar Resource

Operating Principles

Background

Example Installations

Economics

Organizations:

Promoting Solar, Incentives, Training

System Components Solar Collector: absorb radiation and transfer heat to fluid (water/air/glycol) Mounting Hardware Holds collector: wind & seals roof Plumbing & Pumps Move fluid to/from collector Controls Turn pump on/off Freezing Over temperature Heat Exchanger Storage Tank

Solar Collector:

absorb radiation and transfer heat to fluid (water/air/glycol)

Mounting Hardware

Holds collector: wind & seals roof

Plumbing & Pumps

Move fluid to/from collector

Controls

Turn pump on/off

Freezing

Over temperature

Heat Exchanger

Storage Tank

Heat Transfer Conduction Loss Back & Sides Conduction, Radiation and Convection Loss Top Cold Fluid (Water) IN Hot Fluid (Water) OUT ABSORBER PLATE (Metal) Radiation Insolation IN COVER PLATE (Glass/Polymer) “ Good” Greenhouse Effect ~Transparent to Incoming radiation ~Opaque to Outgoing radiation Trap Energy and Transfer to Fluid

Sun Earth/AET Collector

Thermomax http://www.thermotechs.com/Downloads/How%20Works.pdf

Thermomax “ heat pipe” high conductance thermal conductor. Heat transfer rate is thousand's times greater than solid heat conductor closed container consisting of a capillary wick structure and a small amount of vaporizable fluid. employs an evaporating-condensing cycle accepts heat from an external source uses this heat to evaporate the liquid (latent heat) releases latent heat by condensation (water header) return condensed fluid back to the heat zone. http://www.thermotechs.com/Downloads/How%20Works.pdf

“ heat pipe”

high conductance thermal conductor.

Heat transfer rate is thousand's times greater than solid heat

conductor

closed container consisting of a capillary wick structure and a small amount of vaporizable fluid.

employs an evaporating-condensing cycle

accepts heat from an external source

uses this heat to evaporate the liquid (latent heat)

releases latent heat by condensation (water header)

return condensed fluid back to the heat zone.

Differential Control

Collector Types Flat Plate with Cover w/o cover (pool) Evacuated Tube “Thermomax” Concentrating Collector Parabolic Trough

Flat Plate

with Cover

w/o cover (pool)

Evacuated Tube “Thermomax”

Concentrating Collector

Parabolic Trough

Selective Surface Absorber Plate absorbs large fraction (>.9) of energy But doesn’t emit a lot of energy (>.1)

Direct (open loop) Pumped Circulate Potable water Pump turns on when water in collector 15-20 deg warmer than tank Turns off when 3-5 deg warmer than tank Couple of freezes/year OK Recirculates warm water if collector starts to freeze http://www.fsec.ucf.edu/en/consumer/solar_hot_water/homes/system_types.htm

Circulate Potable water

Pump turns on when water in collector 15-20 deg warmer than tank

Turns off when 3-5 deg warmer than tank

Couple of freezes/year OK

Recirculates warm water if collector starts to freeze

PV operated system Pump turns on when enough sun to run pump Collector is warm too South http://www.fsec.ucf.edu/en/consumer/solar_hot_water/homes/system_types.htm

Pump turns on when enough sun to run pump

Collector

is warm too

South

Indirect Pumped System Closed Loop Northern climates Circulate Antifreeze solution Heat Exchanger Differential Controller http://www.fsec.ucf.edu/en/consumer/solar_hot_water/homes/system_types.htm

Closed Loop

Northern climates

Circulate Antifreeze solution

Heat Exchanger

Differential Controller

Drain Back System Remove all water from collector when freezing When pump off, collectors drain by gravity to inside tank

Remove all water from collector when freezing

When pump off, collectors drain by gravity to inside tank

Integral Collector Storage (ICS) System Collector is storage Cold water supply flows directly to collector where heated Then into tank with aux heater Florida etc.

Collector is storage

Cold water supply flows directly to collector where heated

Then into tank with aux heater

Florida etc.

Thermosiphon System Tank above collector Circulate by density differences Hot water rises from collector into tank Cold water in tank flows down into collector be heated Need to protect from freezing

Tank above collector

Circulate by density differences

Hot water rises from collector into tank

Cold water in tank flows down into collector be heated

Need to protect from freezing

Drain back system Installed Basement Collector

How much Energy required? BTU saved is BTU doesn’t have to be generated Low flow shower heads Cold water laundry

BTU saved is BTU doesn’t have to be generated

Low flow shower heads

Cold water laundry

Available Solar Resource Sun Position Time Hour Month Latitude Longitude Incident radiation Beam Diffuse Reflected Clouds Collector Tilt Ground Conditions Albedo Shading Solar Pathfinder

Sun Position

Time

Hour

Month

Latitude

Longitude

Incident radiation

Beam

Diffuse

Reflected

Clouds

Collector Tilt

Ground Conditions

Albedo

Shading

Solar Pathfinder

Available Solar Resource Combination Weather Data Empirical Results Computer simulation

Combination

Weather Data

Empirical Results

Computer simulation

NREL

F Chart: Fraction from Solar F Avg=0.65

Thermomax Burlington VT (simulation)

Burlington VT (simulation)

System Economics 1 sqft/gal storage@80 gal= 80 sq ft collector North Country weather (Massena) Electric bill $0.15 kWh Paid by 20 yr mortgage

1 sqft/gal storage@80 gal=

80 sq ft collector

North Country weather (Massena)

Electric bill $0.15 kWh

Paid by 20 yr mortgage

System Cost

Simple Payback $5000/$500- 10 years BUT Payback on Couch? Payback on Elec Water heater? need hot water! Need better model of usage Did not include incentives CO2 reduction

$5000/$500- 10 years

BUT

Payback on Couch?

Payback on Elec Water heater? need hot water!

Need better model of usage

Did not include incentives

CO2 reduction

Incentives: DSIRE http://www.dsireusa.org/ tracks federal financial incentives for renewables Especially residential

http://www.dsireusa.org/

tracks federal financial incentives for renewables

Especially residential

Federal Tax Incentives

NYS Tax Incentives

System Economics Breakeven!

Organizations NYSERDA-NYS Incentives, R&D, Edcn ISPQ-Training and Certification NABCEP Training and Certification IREC SRCC- Solar Rating Certification Center Industry -Testing of Collectors DSIRE- Incentive database

NYSERDA-NYS Incentives, R&D, Edcn

ISPQ-Training and Certification

NABCEP Training and Certification

IREC

SRCC- Solar Rating Certification Center Industry -Testing of Collectors

DSIRE- Incentive database

IREC http:// www.irecusa.org / Trade organization Consumer Protection Education Quality Installation Skills Installers Trainers Master Trainers

http:// www.irecusa.org /

Trade organization

Consumer Protection

Education

Quality

Installation Skills

Installers

Trainers

Master Trainers

IREC: Task Analysis

Training and Certification SUNY Canton AREA Program NYSERDA ISPQ Certification NABCEP Certification

SUNY Canton

AREA Program

NYSERDA

ISPQ Certification

NABCEP Certification

Questions?