Pee-Power Urinal

Target SDGs

Market Suggested Retail Price

$850.00

Target Users (Target Impact Group)

Community, Public Sector Agencies, NGOs

Distributors / Implementing Organizations

The Pee-Power technology is the result of a partnership between researchers at the Bristol Robotics Laboratory, a collaborative partnership between the University of the West of England (UWE Bristol) and the University of Bristol, and Oxfam. This technology is also funded by Bill and Melinda Gates Foundation.

Manufacturing/Building Method

Manufactured at the Bristol Robotics Laboratory. This product was built from ceramic Microbial Fuel Cells (MFC) stacks with dimensions 10.2 cm (length), 3.5 cm (outer diameter), 2.5 cm (inner diameter) and approximate volume of 49 mL. For the building method, the anode electrodes were made from 337.5 cm² of carbon fiber veil with two 10 cm length strips of 0.25 mm diameter stainless steel wire folded so as to form a spiral brush. The cathode was prepared by painting two coats of a micro-porous layer (MPL) on the outer surface of the ceramic cylinder.

Intellectural Property Type

Patent

User Provision Model

Directly from designer. The technology has been implemented in Seseme Girls' School in Uganda.

Distributions to Date Status

The first is a urinal based on a superstructure, which has been installed on the University campus. It produces enough electricity to power four LED light bulbs in the cubicle.    

Design Specifications

The Microbial Fuel Cell (MFC) is an energy converter, which turns organic matter directly into electricity, via the metabolism of live microorganisms. The bacteria break down organic molecules and generate electricity - that could run on the organic molecules found in urine, such as uric acid, creatinine and small peptides. The electricity output from MFCs is relatively small and these low levels of energy are stored and accumulated into capacitors or super-capacitors, for short charge/discharge cycles. Smaller cells have higher energy densities and are more efficient, so the technology relies on miniaturization and multiplication, building stacks of cells. The latest models of MFC use ceramic cylinders. There is a continuous stream of urine passing through a series of fuel cells, that keeps up the electricity production by constantly 'feeding' the bacteria. The electricity is collected by an energy harvesting board. Ceramic cylinders were purchased from International Biological Laboratories (Haryana, India) and were made from porous ceramic (earthenware) material. The average dimensions were 10.2 cm (length), 3.5 cm (outer diameter), 2.5 cm (inner diameter), with an approximate volume of 49 mL. The closed ends of the cylinders were removed so that the 3D printed lids (air-gap adaptors – see below) could be introduced at both ends (see Fig. 1). The anode electrodes were made from 337.5 cm² of carbon fiber veil (PRF Composites, Dorset, UK) with two 10 cm long strips of 0.25 mm diameter stainless steel wire (SWC, UK) folded so as to form a spiral brush. The cathode was prepared by painting two coats of a microporous layer (MPL) on the outer surface of the ceramic cylinder.

Product Schematics

Technical Support

Users can contact the manufacturer on their website.

Replacement Components

N/A

Lifecycle

In theory, infinite lifetime

Manufacturer Specified Performance Parameters

Manufacturer performance targets with the second field-trial (2016, UK) was to study the feasibility of SSM-MFC to be deployed as an electricity-generating sanitation solution in decentralized areas for periodic usage.

Vetted Performance Status

It was tested from February–May 2015 and demonstrated the feasibility of modular MFCs for lighting, with University staff and students as the users; the next phase of this trial is ongoing. The second is a larger urinal that has been tested during the Glastonbury Music Festival at Worthy Farm, Pilton in June 2015. It demonstrated the capability of the MFCs to reliably generate power for internal lighting, from a large festival audience (?1000 users per day). Field results of the system (2016, UK's music festival) under uncontrolled usage indicate an optimal retention time for power production between 2.5 h and ~9 h. When measured (HRT of ~11h40), the COD decreased by 48% and the total nitrogen content by 13%. Compared to the previous Pee-Power field-trial (2015, laboratory) the present system achieved a 37% higher COD removal with half the HRT. The 2016 setup produced ~30% more energy in a third of the total volumetric footprint (max 600 mW). This performance corresponds to ~7-fold technological improvement.

Safety

Unknown

Complementary Technical Systems

None

Academic Research and References

Compliance with regulations

Unknown

Evaluation methods

Lab testing and research; short term real-life situations. The evaluation criteria used to determine an appropriate use-case are:

• Clear identified need for sanitation and risk of gender based violence
• Capacity and enthusiasm of the Oxfam Country team to participate and monitor the project.
• Conducive external environment including no significant import restriction/prohibitive tariffs on goods.
• Supportive host government/local leadership.
• Stable security.
• Expectation that the camp is semi permanent in nature and will continue well beyond the project duration.

Other Information

The project has been funded by the Engineering and Physical Sciences Research Council (EPSRC), the Gates Foundation and the Technology Strategy Board. Expert advisors have stated that the prototype models seem to be effective and that the MFC technology is su?ciently mature to be introduced as a carbon neutral pre-treatment system that would positively impact the management of liquid waste stream both in urban and rural areas. However, further testing should give people confidence in the value of this technology. Expert advisors have expressed concerns about possible problems that have not yet been faced. For example, other microbes could displace the ones that are generating electricity, thus causing it to fail. Only long-term use in practical applications can prove whether this might happen.