A burst water main illustrates the power that could be tapped from a city’s system.
In 2009, Coenraad van Blerk, a director of Green Hydro Power, obtained a patent from the South African patent office for an "electricity generating arrangement" but two years later Rand Water put out a tender for what he has claimed is the same thing.
At stake for Rand Water is a tender to build four hydropower plants on Johannesburg's vast hydraulic network, which could generate R43-million worth of electricity each year.
For Van Blerk and Green Hydro Power, it could be much more. The patented idea is to generate electricity by harnessing hydropower produced by fast-flowing water, such as that in municipal water pipes. Pressure-reducing valves, which are used to slow down fast-streaming water as it decants into dams or reservoirs, are replaced with turbines linked to generators to create electricity that can be fed into the national grid. The concept requires a high volume of water, such as that found in densely populated areas, such as Johannesburg, which has a vast hydraulic network and hundreds of reservoirs.
In March 2011, Rand Water issued a tender to build four hydropower plants in its network, which Van Blerk believed could infringe on his patent. Van Blerk and Green Hydro Power alerted Rand Water of this and filed an application for an interdict to restrain the state-owned enterprise from awarding the tender.
Withdrawn tender
According to documents before the court, Rand Water has argued that Van Blerk's patent should be revoked as it "is not novel and does not involve an inventive step".
The first tender was withdrawn and a second closed tender advertising for the construction of four hydropower plants was issued with a closing date of May 10 this year. According to court papers, Rand Water issued the second tender subject to caveats about patent infringement.
Rand Water claims that, based on Eskom's current tariffs, it stands to lose R43-million annually in electricity costs and loss of revenue from possible excess sales to Eskom.
Eskom says it engaged with Green Hydro Power approximately two years ago but no formal application was registered. Patent law experts say it fairly simple to obtain a patent in South Africa.
Doryn Myers, director of Myers IP, said, in order to obtain patent protection, the invention had to be novel and inventive, and Theo Doubell, a partner of Bouwers Inc, an intellectual property law firm, said obtaining a patent in South Africa was easier than in other countries such as the United States where there were substantive examination proceedings.
"You will get a patent granted in South Africa if you satisfy the formal requirements," he said.
The vailidity
Under South African law, a granted patent is assumed to be valid and in force and the onus to prove otherwise is on the infringer. If someone or a company is sued or interdicted for infringement, the validity of a patent is often assessed in court.
Doubell said most tender processes allowed for a relaxation if there was proprietary technology, such as patented technology, and, if an idea was subject to a patent, that would certainly be a major consideration. Rand Water is also opposing a pending application for an amendment of the patent and has argued that, because Van Blerk and Green Hydro Power sought to amend the claims in the specification of the patent, they were "obviously conceding that the patent was invalid in its present form".
But Doubell said an amendment to a patent was common. Typically, patent applicants and their attorneys erred in the applicants' favour by drafting patent applications that were broader rather than narrow in scope. If the scope of the patent was too broad and included prior art (existing technologies or know-how), the inventor could amend the claims of the patent in order to narrow the scope.
An acceptable process
"[But] the law only allows a patentee to make the scope of the claims narrower [not broader]," Doubell said.
Myers agreed that amending a patent was an acceptable process. "It's a common step, a reasonable step and an expected step."
Both the interdict and the patent amendment are on hold while seven interlocutory [interim] and other applications play out in court. These applications centre around the question of why Rand Water refuses to disclose some of its documents that should be publicly available.
In response to questions, Van Blerk, Green Hydro Power and Rand Water told the Mail & Guardian the legal proceedings were sub judice and, therefore, they could not comment on the matter.