In January 1921, a group of local body representatives from throughout Central Hawke's Bay held a meeting in Waipukurau with the aim of forming a Power Board to install a network for the supply of electricity to homes and businesses in the district.

To form a Power Board, they had to present a submission signed by 25 per cent of the district's ratepayers to the Governor General. Their submission was successful and the Central Hawke's Bay Power Board was constituted by gazette notice on 19 October 1922. The first election for board members took place on 19 December and the first directors were: E A Goodger (Waipukurau Borough), W H Rathbone (Waipawa Borough), A C Russell (Waipukurau County), F J Witherow, R A Fraser, J A Kerr (Waipawa County), W Malenoir, C Pattison, T Butler (Patangata County).

On 3 October 1923, a poll of ratepayers gave authority to raise the sum of 150,000 pounds to reticulate (install a network of powerpoles and electricity carrying cables) the district.

At 2 p.m. on Tuesday 20 October 1925 the Onga Onga sub station was officially opened. However it had been in use for some weeks before that with the power coming from the Mangahao hydro-electric station at the foothills of the ranges near Shannon. The supply from this was, to say the least, erratic and shut downs were not uncommon, resulting in concern from the hospitals and in particular the then Pukeora Sanatorium.

The reticulation of the district went ahead and by 1928 lines were as far as Wanstead and in 1936 Porongahau went live.

The Board began manufacturing its own concrete poles in 1937 at a cost of four pounds, four shillings and ten pence, and today Centralines still makes all its own concrete poles.
The war years (1939 - 1945) brought continued reticulation to a standstill with many staff on active service and supplies and material difficult, if not impossible, to get.

After the war, Mr E Bunn took over the private line erection contract from his father and he continued putting up lines until July 1950 when the board decided it would be responsible for all network development. The board continued to do this until 1956 when Mr Yewen was employed as line contractor and he completed the reticulation of the district.

Power shortages continued to plague the board as far back as 1941 and this had a major effect on the board's income. However, the problem lessened and in 1956 a house was erected at Porangahau for an inspector/faultman.

During the next three decades the Power Board business continued to build its business, and the districts network electricity assets went from strength to strength. A print from an early "Central Hawkes Bay Electrical Power Board" stamp

In 1991, under new company reforms the old Power Board Structure went out of existence, and was replaced with CHB Power.
In 1998 new Government legislation deregulated the electricity sector, requiring the company to separate the ownership of its line and energy supply business.

The Electricity Reform Act 1998 states that owners of a line network business cannot also sell electricity. After careful consideration the Directors decided to retain the local asset and in November 1998 sold the energy business. As a result, CHB Power changed its name to Centralines Limited on 1 July 1999.
This ended a significant era in the company's history after retailing electricity to the Central Hawke's Bay for 77 years.

Further innovations in Centralines administration were introduced in April 2001, with the signing of a one-year contract, with neighbouring line network company Scanpower from Dannevirke, for the supply of management services to Centralines. This initiative broke new ground in the industry and was considered very successful.

Centralines in a continuing effort to seek opportunities to enhance the operation of its business was able to negoitate their latest management contract with Hawke's Bay Network, signed on 1 October 2002, for a period of five years, thereby providing a certain level of consistency to the management and direction of the company.