Business Installations – Hotels
Right Sized, Right Temperature Solar Dynamics Hot Water Systems will satisfy 98% of a business’s hot water needs in the temperature range of 120 to 160 degrees F.
The hospitality industry in the Caribbean is the largest user of hot water for guests personal care, kitchen sanitation and hygiene. Guests in the average hotel room consume 40 gallons of hot water per day.
Some of the best known Caribbean hotels – Sandals in St. Lucia, Mango Bay in Barbados, Almond in Barbados and St. Lucia, Spice Isle in Grenada, Coco Palm and Bay Gardens in St Lucia are experiencing the efficiency and benefiting from the savings of energy and money through the Solar Dynamics Hot Water System.
UNEP Report on Solar Water Heating in the Hotel Industry- Bay Gardens Hotel, St Lucia
Bay Gardens installed solar water heating systems to reduce operating costs. The hotel’s general manager, Ms. Waltrude Patrick points out that, “While overall costs on electricity have gone down by 40% with the help of SWH, actual savings depends on the occupancy rates at the hotel.”
The system, however, is integral to the finances of the hotel. Saint Lucia has high electricity and liquefied petroleum gas (LPG) rates averaging around USD 0.38/kWh (2013-2014) and USD 0.69/lb respectively, for the hotel sector (LUCELEC 2015).
Like most Caribbean islands, hot water produced with LPG or electricity drawn from the grid results in relatively high water heating bills.
Since opening in 1995, Bay Gardens began exploring options to reduce their operating costs and soon after installed SWH system across the property with the help of Solar Dynamics, the only SWH supplier and installer in the region at the time. When asked what would happen if Bay Gardens were to move back to conventional electric heating, the maintenance manager, Kenneth Augustin shared, “Our operating costs would double!”
UNEP Report on Solar Water Heating in the Hotel Industry- Turtle Beach Resort, Barbados
The solar water heating system for Turtle Beach was installed in 1997 by Solar Dynamics. In all, the systems measure 251 sq.m., and are designed to serve 100% of the resort’s hot water load. Even with the occasional use of electrical boosters, the resort has reduced its energy bill for heating water by 95%.
Rate of ROI
Each hotel can generate a high rate of return, over 45% on the investment in the Solar Dynamics Hot Water System. Each room consumes the equivalent of two barrels of oil per year to heat water. The rate paid for electricity is generally 4.5 times the cost of oil.
Where a boiler is being used for hot water in a hotel or laundry, preheated water by solar is an effective way of reducing your fossil fuel demand.
Each hotel room would require 2000 kWh of energy per year to satisfy the hot water needs of guests . At today’s average cost of US$.70 per kWh for electricity, the cost for hot water is US$1.400.00 per room per year.
The Solar Dynamics hot water system will efficiently provide 95% or US$1.330.00 of this hot water effortlessly. The system will provide hot water for 347 days of the year. A 300 room hotel would save up to US$400.000.00. per year, using Solar Dynamics Hot Water , as compared to electric water heating.
The capital cost of solar water heating being an average of US$ 2.500.00 per room; the solar hot water system will pay for itself within two years, and yield a return on investment of 53% on capital, annually. Alternate options such as leases can be discussed. Performance and temperature guarantees eliminate the risk of investment failure.
Sizing recommendations for the hospitality industry
Solar hot water systems absorb the sun’s heat during the day and store the heated water throughout the 17 hour non-solar period of night and early morning.
Most hot water is consumed in the non –solar period between 6.00 pm and 8.00 am the following morning.
During this period, the heated water used, is replaced by incoming cold water. This cold water being heavier, remains in the lower part of the storage tank.
Adequate volume is therefore required to avoid having to resort to electrical back-up boosting (it is less expensive to adequately size the system than to be frequently using the back-up electrical booster.
The volume found to be right sizing is as follows:
Per guest at maximum occupancy:
15 gallons per person for regular shower heads.
20 gallons per person for rain shower equipment.
20 gallon per person for tub facilities
20 to 25 gallons per person for Jacuzzi facilities.
The recently concluded UNEP study on solar water heater installations in hotels in the Caribbean, included two of the hotels equipped by Solar Dynamics Ltd, Bay Gardens in Saint Lucia, and Turtle Beach in Barbados. They reported a 95 % to 100% satisfaction with the performance of their systems. These systems were sized on the basis of 20 gallons per person and 40 gallons per 2 person room.
Use of Boosters
Where there is the need to use the back up booster frequently, investigations should be carried out to determine the cause. In some cases, there is a leak on the hot water distribution line or at a tap. Should the installed capacity of the solar water heater be consistently below the needs of guests, the capacity of the system should be increased.
Every effort should be made to avoid the frequent use of the booster, by ensuring that the capacity is adequate. Electrical boosters whether 1500 watt 110 volt or 3000 watt,220 volt impact severely on your demand KVA. or the peak power demand for which you are billed. It is less expensive to provide an adequate volume of solar heated water, using free solar energy (a one time cost) than to pay peak rates for supplementary energy on an ongoing basis.
Solar Dynamics Ltd discourages the practice of leaving boosters in the “on “position. Even though the thermostat setting may be low, the booster will still be in use needlessly, as the booster is installed in the lower part of the storage tank which receives the cold replacement water.