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Solar Water Heaters Pros, Cons, and Savings Calculations in 2024

· 3 min read
D Balaji
D Balaji
Lead Design Technologist

Solar water heaters have become a common sight in households, especially in southern India where the weather is ideal for harnessing solar energy. With over five years of experience dealing with solar heaters, both in my home and those of friends, I've gathered some insights on the advantages, disadvantages, and cost savings associated with these systems.

3 Advantages of Having a Solar Water Heater​

  • Instant Hot Water No need to turn on the geyser and wait for it to heat up. For families with many members, this is a game-changer. My family has become accustomed to having instant hot water 24/7.

  • Reduced Electricity Bill Using solar energy means you save on electricity costs since you’re not using the electric geyser to heat water.

  • Efficient Use of Solar Energy Apart from drying clothes, it's a great way to utilize solar energy efficiently.

3 Downsides of Having a Solar Water Heater​

Despite the benefits, there are notable challenges with continuous ownership:

  • Water Shortages During summer, water shortages are common. If your overhead tank runs dry, the solar tank can't cool down, leading to cracked or broken glass tubes. If a glass tube breaks, water gushes out, potentially damaging other tubes due to the solar tank being almost empty.

  • Vacation Planning When going on vacation, ensure your overhead tank is full. If it runs dry due to evaporation, leaks, or usage, your solar heater could be damaged. Issues like monkey problems, stones, or aerial firecrackers can also break the glass tubes.

  • Plumbing, Tank Quality, and Hard Water The long-term success of a solar water heater depends on these factors. Hard water requires periodic servicing, which can cost around ₹2500. Some solar tanks, made of steel alloys, can corrode and leak. The heat from the solar tank can deform pipes, so consult with plumbers about pipe quality. Hard water exacerbates these issues, damaging water-carrying devices.

Cost of Investment and ROI Worries​

Here are the numbers from my ownership, to help you with a cost-benefit analysis:

Expenses​

2019:

  • Purchased Solar device: ₹25,000

  • Solar piping and taps: ₹5,000

  • Installation labor: ₹5,000

2023:

  • Glass tube replacement (1 tube): ₹2,000

  • Service to remove salt every 2 years: ₹3,000

Maintenance Costs:

  • Every 2 years: ₹4,000 for upkeep and salt removal

  • Every 10 years: ₹20,000 for plumbing overhaul

  • Additional expenses due to unexpected damage: ₹10,000

Expected Product Life: 20 years

Issues faced in 5 years: Tank leak, broken glass tube, unfriendly service personnel, and uncooperative dealer.

Potential Savings​

Annual Electricity Bill Savings: ₹6,000 (₹500*12)

Financial Summary​

  • Cost of Ownership in 20 years: ₹105,000 (approx.)

  • Potential Savings: ₹120,000 (approx.)

To recover the costs, avoid repairs due to water scarcity, monkey problems, etc.

Summary​

While the pros and cons are nearly balanced, the convenience of having hot water readily available is a significant advantage. Purchase solar heaters from reputable dealers and ensure they provide good after-sales service. Many brands are local with informal dealer networks, so check their service commitment beforehand. For instance, a reputed brand might have only one service person for all of Bangalore and nearby districts.