Solar Water Heating

What do SWH systems provide?

• Domestic Hot Water• Process Heat• Swimming Pool

Heating

…but also…

• Increased hot water storage• Extended swimming

season (pool heating)

Components of SWH Systems

Unglazed Solar Collectors

• Low cost

• Low temperature

• Rugged

• Lightweight

• Seasonal pool heating

• Low pressure• Poor performance in cold or windy weather

Glazed Flat Plate Solar Collectors

• Moderate cost

• Higher temperature operation

• Can operate at mains water pressure

• Heavier and more fragile

Evacuated Tube Collectors

• Higher cost

• No convection losses

• High temperature

• Cold climates

• Fragile

• Installationcan be more complicated

• Snow is less of a problem

Solar Water Heating Project Considerations

• Factors for successful projects:• Large demand for hot water to reduce importance of fixed costs

• High energy costs (e.g. natural gas not available)

• No reliable conventional energy supply

• Strong environmental interest by building owner/operator

• Daytime hot water loads require less storage

• Lower cost, seasonal systems can be financially preferable to higher-cost year-round systems

• Maintenance similar to any plumbing system, but operator must be committed to timely maintenance and repairs

Domestic Hot Water Systems

• On-grid, need a committed homeowner• Can have long payback when energy prices are low• Systems provide 20 to 80% of hot water

• Off-grid or where the energy supply is unreliable

Swimming Pool Systems• Low-cost unglazed collectors

• Summer pools in cold climates• Extend the season in warm climates• For summer use on a year-round pool in cold climates• Can have 1 to 5-year paybacks

• Glazed collectors for heat year-round• Filtration system serves as pump

• Hotels/motels, apartments and office buildings• Health centres & hospitals• Car washes, laundromats, restaurants• Sport facilities, schools, shower facilities• Aquaculture, other small industry

Contd…..

Primotech Solar Water Heating Project Model• World-wide analysis of energy production, life-cycle costs and

greenhouse gas emissions reductions

• Glazed, unglazed, and evacuated tube• Indoor and outdoor swimming pools

(w/ or w/o cover)• Service hot water systems

(w/ and w/o storage)

• Only 12 points of data for Primotech Energy Solutions vs. 8,760 for hourly simulation models

• Currently not covered:

• Changes in service hot water daily loads• Stand-alone service hot water• Systems w/o storage having

high solar fractions• Sun tracking, concentrator & integrated solar collectors

Primotech Energy Solutions SWH Energy Calculation

Conclusions• Unglazed, glazed and evacuated tube collectors provide hot water for many

uses in any climate

• Significant hot water demand, high energy costs, and strong commitment on part of owner/operator are important factors in success

• Primotech Energy Solutions Pvt . Ltd. calculates:

• Service hot water load and swimming pool load

• Performance of solar swimming pool and service hot water systems with or without storage

• Primotech Energy Solutions Pvt . Ltd. is an annual analysis with monthly resource calculation that can achieve accuracy comparable to hourly simulation models

• Primotech Energy Solutions Pvt . Ltd. can provide significant preliminary feasibility study cost savings

Thank You