The local authority is suggesting that schools opt for one of four models to trial methods of delivering the extra hours as flexibly as possible for parents.
Currently nursery provision in schools is based around five two-and-a-half hour sessions, with some schools offering morning-only provision.
Liz Eyre, cabinet member for children and young people, said, 'Officers are finding that the take-up in local authority nurseries is not very high and parents have told them private provision is popular because private providers are more flexible.'
There is no extra funding to support the pilot in schools, but the council will evaluate the scheme throughout the year by talking to heads, governors, parents and practitioners.
Worcestershire is one of the 21 local authority 'pathfinder' areas, which in April started trialling the 15-hour entitlement in private and voluntary nurseries.
Local authorities have received a year's DfES funding to develop models of good practice that deliver the extra hours flexibly, maintain continuity of care and do not pose a threat to a setting's sustainability.
Alison Hitchins, service development manager for early years and childcare at Worcestershire County Council, said that most PVI providers, which account for 80 per cent of early years settings, had signed up for the 15 hours. Many offered it over a minimum of three days.
PVI providers in Worcestershire receive 3.92 an hour, which includes a 20 per cent uplift for one year to deliver the extra hours. Last year, providers received 7.92 for the two-and-a-half hour session.
Ms Hitchins said, 'We are asking PVI providers to see how flexible they can be within the bounds of being sustainable.'
Irene Whittaker, who runs Alvechurch Pre-School and Bordesley Nursery School in North Worcestershire, said, 'Within the hours we're open, parents can choose to take a half-day or a full day, depending on what's available.' Thirty-one of the 44 children registered at the nursery are eligible for the entitlement.
Since the extension was introduced in April, 15 children have signed up for the 15 hours at the nursery, and seven are sharing the hours with another provider.