Several implementation issues have held back Digital PowerLine in North America and the UK. Respectively, the problems are the numbers of users per transformer and the size and shape of light poles.
In North America, a transformer serves from 5 to 10 households while in Europe a transformer serves 150 households. Digital PowerLine signals cannot pass through a transformer. Therefore, all electrical substation equipment needed for Digital PowerLine has to be located after the transformer. Since there are fewer households per transformer in North America, predicted equipment costs are prohibitive. However, this conclusion has been debated. Analysts suggest that 100% subscription rates are possible in the US, and that at such rates Digital PowerLine is profitable. Conventional wisdom suggests that there is a way to make Digital PowerLine profitable in North America, whether it is through bundling a variety of services or higher fees.
Soon after the first trials of Digital PowerLine in the UK, some unanticipated problems arose. Certain radio frequencies were suddenly deluged with traffic, making it impossible to transmit on those frequencies. BBC, amateur radio, and the UK’s emergency broadcasting service were affected. The apparent culprits were standard light poles. Then it became clear that by pure chance British light poles were the perfect size and shape to broadcast Digital PowerLine signals. This situation posed problems not just because of the frequencies involved but also because anyone could listen in on the traffic. Nor.Web is addressing the problem by proposing to lease the frequencies involved from their owners and offering amateur radio operators a new frequency. Negotiations on this topic are currently taking place in London. The privacy issue has not been fully addressed at this point, besides suggestions that all sensitive information should be encrypted.