Texas Renewable Energy Industries Association
and Texas Home Energy Rating Organization
present
“The Latest in Renewables”
Tom Fitzpatrick, Moderator
Panel:
Jimmy Gaffney, EarthTech;
Jim Duncan, North Texas Renewable Energy, Inc.;
Philip Fisher, Solar System Installations;
Steve Gleaves, Bureau Veritas
The National Association of Home Builders is a Registered
Provider with The American Institute of Architects Continuing
Education Systems. Credit earned on completion of this
program will be reported to CES Records for AIA members.
Certificates of Completion for non-AIA members are available
on request.
This program is registered with the AIA/CES for continuing
professional education. As such, it does not include content
that may be deemed or construed to be an approval or
endorsement by the AIA of any material of construction or any
method or manner of handling, using, distributing, or dealing
in any material or product. Questions related to specific
materials, methods, and services will be addressed at the
conclusion of this presentation.
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International Copyright laws. Reproduction,
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© Texas Renewable Energy Industries Association and
Texas Home Energy Rating Organization, 2009
Learning Objectives
For each of three technologies Geothermal
Exchange, Solar PV and Solar Water Heating:
understand what it is
understand opportunities, benefits of its application
understand appropriate/inappropriate situations for
selecting it
understand some of the practical considerations in
installing the technology
understand impacts on energy costs and green ratings
Geo Exchange Heat Pumps
Geo-thermal exchange is using the constant
temperature of the earth to exchange with the
extremes of outside.
The residential market is virtually untapped. You
can offer your client drastically reduced heating
and cooling bills.
This system needs to be implemented in the
overall development/design phase, depending if
it’s a custom home or production building
Preferred Well Field Design
Geothermal Process
The following pictures are presented in
order of installing a geothermal system.
These photos are current jobs that
Earth Tech is completing.
Pressure Grouting each well from the bottom to
top insuring consistent thermal conductivity
Well Field (Closed Loop System) manifold 4 foot
below future parking lot, sand imbedded, and
compacted
House Previously Shown
Square Footage= 4800
Total Tons= 13
Total Wells= 15
Total Cost= $35,000
Average Electric Bill= $250-#300 monthly
Owner estimates about a $14000 premium and his payback on
this will be 2 years. No maintenance, no outside noise from
compressor, estimated life cycle of unit is 23 years (predicts to
be much longer due to being inside and operating out of the
elements, piping has a 50 year warranty, and the pumps have a
30 year warranty
AC Installer Program
Residential new construction AC and
heat pump incentives are fixed at $300
per system
Geothermal incentives are calculated
individually using equipment size and
efficiency inputs
Oncor – www.takeloadofftexas.com
Reducing First Cost Premiums
Installing the wells at the beginning
infrastructure of the development
Marketing to area
Advertising difference from other
developments
Incentives from government and power
companies
Photovoltaic Energy
Photovoltaic Energy
Solar photovoltaics is the simple conversion
process of sunlight to electric power
a technology that has the potential to profoundly
change our civilization as extraordinarily as the
personal computer has.
Onsite PV generates electric power to offset the
demand for traditional centralized utility power.
Onsite generation technology is easily integrated
into both existing and new construction.
PV: Minimizing Need
Many homes built during the latter part of
the last century overlooked the
fundamental potential of passive solar
design, and
integration of energy efficiency
PV: Balancing Costs
Scaling existing PV technology: in order to
generate more power, a larger PV array
(more area) must be utilized (unlike
electronic technologies )
Electronic advancement in technology,
does apply to the “balance of system”
components such as the inverter, often
considered the heart of a PV system
PV: Design
A relatively large, un-shaded and southfacing roof area is needed
standard construction practices are
appropriate for the electrical interface to
be utility grid interactive
PV array wind loads and dead loads are
addressed at the design stage and easily
meet load-bearing standards outlined in
International Residential Code
PV: Tips
By anticipating the potential integration of
residential solar power retrofits, a builder
may declare a new home “solar-ready”
even though a PV installation may not be
a standard part of the new construction
By offering the option of solar PV, the
builder may be a step ahead of
competitors who have not offered
innovative additions to their homes.
Solar Hot Water Heating
Systems
Solar
Hot Water
Heating Systems
Solar Thermal Applications
Single And Multi-family
Water Heating
Restaurant
Swimming Pool & Spa
Heating
Industrial Process Heat
Boiler Make-up Water
Water Distillation/Purification
Hotel
– Service Hot Water
– Laundry
Solar Thermal Applications
In the US, the use of solar thermal systems is most
predominant in the residential market.
Traditionally, the primary use of solar in this sector has
been for swimming pool and domestic water heating as
well as space heating.
Residential applications
• Domestic hot water
• Swimming pool and spa heating
• Space heating
• Water purification/distillation
• Air Conditioning
Administrative Building
Typical Residential
Consumption or Demand
20-gallons per day for first two people, then 15gallons for each additional person
– Family of one or two = 50 gallon system
– Family of four = 80 gallon system
– Family of six or more = 120 gallon system
Solar Conversion Table
Rated in BTU’s or rated in kilowatt hours
1 KW = 3,413 btu’s = $ 0.13
1 KWhr = 11,000 btu’s
Therm = Heating unit equal to 100,000
btu’s
MCF = Thousand cubic feet
Solar Collector
Solar Collector
Solar Water Heater
Direct Solar Water Heating
Referred to as “direct”
because the sun’s heat is
transferred through the
collector directly to the
usable water line; no
antifreeze is required.
When sun is shining, a
pump circulates water
from bottom of a storage
tank through collectors
where it is heated, and
then returned to the tank
for storage and use.
Direct Solar Water Heating
Differential Control senses temperature differences
between water leaving the collector and coldest water in
the bottom of the storage tank. When water in the
collector is hotter than the water in the tank, the
differential control operates the circulating pump.
A small photovoltaic solar panel option is available to
operate the circulation pump, further reducing traditional
energy consumption.
Freeze protection includes a thermally operated valve
installed at the collector (where required) or by manually
draining.
Indirect Solar Water Heating
Referred to as “indirect”
because the sun, through
a roof-mounted collector,
heats fluid circulating in a
closed loop which never
comes in direct contact
with usable water stored
in an insulated tank.
Accommodates climates
where freezing occurs
more frequently.
Indirect Solar Water Heating
Differential Control senses temperature differences
between water leaving the collector and coldest water in
the bottom of the storage tank. When water in the
collector is hotter than water in the tank, the differential
control operates the circulating pump.
A Heat Exchanger located within the storage tank
maximizes the heat transfer from the antifreeze solution
to the coldest water in the storage tank.
A small photovoltaic solar panel option is available to
operate the circulation pump, further reducing traditional
energy consumption
Drain Back Series
The Drainback Series is
an indirect system.
Referred to as “indirect”
because the sun, through
a roof-mounted collector,
heats fluid circulating in a
closed loop which never
comes in direct contact
with usable water stored
in an insulated tank.
Drain Back Series
Removes all water from the collectors, and their pipelines to ensure
they never freeze when the system is not producing heat (drain
mode).
Each time the pump shuts off, the water in the collector(s) and
piping, which are mounted at a slight angle, drains into the insulated
reservoir tank.
A sight glass attached to the reservoir tank indicates that the
collector(s) has been completely drained.
A Differential Control senses temperature differences between water
leaving the collector and the coldest water in the bottom of the
storage tank. When the temperature of the water in the collector is
hotter than the water in the tank, the differential control operates the
circulating pump.
Less moving parts allows for fewer maintenance concerns.
Drain Back Series
“DB” System – (internal heat exchanger in storage tank)
– The heat exchanger wraps around the perimeter of the
storage tank, heating the potable water in the tank.
“DX” Drainback System - (internal heat exchanger in
Drainback reservoir) - drainback reservoir contains a
built-in heat exchanger. As the heat transfer fluid is
circulated through the solar collector loop,
simultaneously, water is circulated from the hot water
tank through the finned coil heat exchanger inside the
reservoir.
Free Flow Systems
“thermosyphon” system
collector positioned lower
than tank operates on the
principle of natural
convection
sun heats the water in the
collector, causing the
water to rise into the tank
colder, heavier, water in
the tank then sinks into
the collector.
continuous natural cycle
Free Flow Systems
Thermosyphon systems are widely accepted throughout
the world today.
They are automatic, simple, and reliable.
Thermosyphon Systems do not require a pump or
control.
There are no moving parts which allows for minimal, if
any, maintenance concerns.
NAHB Green Building Scoring
Impacts
Presented by Steve Gleaves, Bureau Veritas
NAHB Points Scale
Three levels of certification
–Bronze requires 237 points
–Silver requires 311 points
–Gold requires 395 points
Energy Efficiency Points
Minimum 37 points required, 100 available
Prescriptive Path
Performance Path
– Based on ResCheck, downloadable at
www.energycodes.gov by anyone
– Evaluates shell, modified by mechanical
– Items not evaluated by ResCheck are found
in NAHB Scoring Tool
What ResCheck Evaluates
Ceiling area and R-Value
Wall area and R-Value
Window area, U-Factor, & Solar Heat Gain
Floor area and R-Value
Door areas and U-Factor
BASIC Heating and Cooling Trade-off
What ResCheck Does Not
Geothermal performance
Solar Technologies
Duct leakage
Orientation of building
Water heating efficiency
Infiltration rates
NAHB Scoring Tool addresses these
Summary of Scoring Impacts
NAHB
Prescriptive
GSHP
Solar DHW
16
Photovoltaic
17
8
Why Two Paths?
Transparency & Predictability in
Prescriptive Path (baseline for budget)
ResCheck supports BASIC design
improvement credit
ResCheck may cut implementation costs
as design impacts specification costs
Simple to run, highly accessible
Find the path that fits your business!
This concludes The American Institute of Architects
Continuing Education Systems Program
www.treia.org
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