Often located in remote and ecologically sensitive destinations, off-grid eco-hotels, camps, and lodges present a unique challenge for designers, developers, and operators who aim for sustainable systems. Off-grid systems require on-site generation of all electricity, domestic and potable water, as well as maintenance of on-site sewerage treatment.
In 2018 Luxury Frontiers (LF), an architecture and design firm specializing in sustainable design and light-on-earth structures, assisted in a comprehensive refurbishment of Belmond Safaris’ Savute Elephant Lodge (SEL) located in the Chobe National Park in Northern Botswana, providing a stellar example of a sustainable off-grid operation by encompassing place, people, materials, electricity generation, water, and waste.
In keeping with Botswana’s legislation, and in order to fulfill the lease requirements set out by Belmond in favor of their sustainable principles, all concrete structures were removed during the refurbishment of the lodge. All accommodations and structures were rebuilt to be semi-permanent which was achieved by placing the structure onto timber-based platforms (as opposed to using traditional foundations) with a unique canvas-tented theme specifically designed to fit in with the surrounding aesthetic.
During construction, large vehicles transporting materials to and from the site can cause damage to the environment and increase the carbon footprint of off-grid projects. To reduce the number of vehicles visiting the site and to promote Leave No Trace principles, LF implemented a diligent logistics strategy by ensuring each truck carrying new material for the rebuild departed Chobe National Park with a full load of concrete rubble and other waste.
Involving local communities in projects is an important part of the Luxury Frontiers Sustainability Framework. For SEL, LF contracted a local construction company (Lodge Builders Botswana) for the project, with locals comprising 98% of the building crew. Furthermore, the accommodation designs included roof coverings constructed using local grass thatching purchased from communities in Northern Botswana.
All base structures were completely refurbished using repurposed Zimbabwean teak decking. Reclaimed gum poles were reused in the back of house buildings and the roof structures of the new accommodations.
In keeping with the light-on-earth mission, the main area structures were completely rebuilt using only timber and canvas in a unique architectural style. The internal flooring was made from regional Saligna Gum, a Forestry Stewardship Council-certified timber. The external decking and facias were constructed using bamboo, which is the highest-rated green alternative to timber products and has a neutral carbon footprint.
Electrical Power Generation
As part of the refurbishment, LF replaced the 250kVa diesel-powered generator with a new 212kWp Tesla Photo Voltaic (PV) Solar system as the primary power source with additional backup generators. On a typical day, the PV solar system will power the lodge completely during daylight hours while charging the batteries to power the nighttime hours. The system comprises a solar farm of 2500 m² with 665 PV solar panels, which work in conjunction with 2 backup generators in case of battery depletion or emergencies.
Additional power management designs include:
· LED-based lighting not exceeding 10watts.
· Invertor-based air-conditioning units which reduce power consumption by a third and noise levels by half.
· Energy efficient units for refrigeration.
· Inclusion of low wattage, power-efficient fans throughout the lodge, including staff rooms.
· Thermodynamic geysers for each of the guest units, which heat water through a combination of ambient temperature and electrically efficient pumps. Staff and back-of-house areas are fed by a central solar-heated hot water system.
On a typical day, SEL consumes an estimated 25,500 liters of water and generates 20,000 liters of sewerage waste. To manage these day-to-day requirements, Luxury Frontiers implemented an off-grid system for the lodge where water is pumped from two boreholes to a central raw water sewerage area. From there, the water passes through a filtration plant which then passes through a reverse osmosis (RO) plant with remineralization for distribution to guest areas. Single-use plastic is reduced by supplying guests with a reusable aluminum water bottle to refill on-site with either still or carbonated filtered water at chilled temperatures.
Treated Sewage Waste (Effluent)
The outdated sewerage system was replaced with a new anaerobic Sewerage Treatment Plant (STP) with the capacity to treat 25 000 liters of effluent per day. The STP uses a natural process of bacterial digestion and waste degeneration to break down effluent and kill off any remaining bacteria before distributing the water through the landscape design using an irrigation system, allowing for natural evaporation and permeation. The use of paraben-free cleaning products and guest amenities (such as shampoos and lotions) helps to ensure that the effluent waste system is properly maintained.
All other waste materials, such as food, paper, and other biodegradable waste are turned into compost using an accelerated Earth Cycler On-site Food Composter, which can process up to five tons of waste per month. This compost is not used on-site as it could potentially cross germinate foreign plant species onto the Chobe National Park land. Instead, the compost is bagged and distributed for use to local farmers and communities or appropriately disposed of through recycling initiatives in the neighboring town of Maun.
Sustainable systems in off-grid locations are challenging but necessary to complement the natural beauty of the destination, enrich the local community and preserve surrounding areas for future generations.