I think these FTSE 250 shares could provide exceptional returns over the next decade and a half. Here’s why I think they’re worth serious consideration today.

1. NextEnergy Solar Fund

Investing in electricity generators could be a great long-term play as global power demand rapidly increases.

In a fresh report this week, the International Energy Agency (IEA) predicted worldwide energy demand growth “will be the equivalent of adding an amount greater than Japan’s annual electricity consumption every year between now and 2027“.

The IEA also upped its growth forecasts for the period, to 4% each year from 3.4% previously. It says demand will be driven by increases in data centres, electric transport, industrial production, and air conditioning.

These are long-term trends that mean shares like NextEnergy Solar Fund (LSE:NESF) could prove great investments over time. This particular company, as the name suggests, generates power from renewable sources which it sells to energy suppliers.

With the fight against climate change stepping up, investing in renewable energy stocks could be a safer bet than companies that generate power from ‘dirtier’ sources.

There is danger in this approach, though. Power generation can sink when solar radiation levels fall, putting NextEnergy’s profits in jeopardy.

However, the FTSE 250 firm’s broad geographic footprint helps reduce this threat at group level. Roughly 85% of its solar assets are in the UK, though they are spread up and down the country. It also produces power in parts of Southern Europe.

I think NextEnergy shares are extremely attractive at current prices. At 66.3p, the fund trades at a 30.4% discount to its net asset value (NAV) per share.

It also has a 12.3% dividend yield, which is one of the largest on the FTSE 250.

2. Springfield Properties

Housebuilders like Springfield Properties (LSE:SPR) also have significant long-term potential as the UK’s population grows.

The Office for National Statistics (ONS) research predicts the number of Brits will leap almost 5m in the decade to 2032. Such potential growth provides excellent opportunities for creators of residential property.

The government plans to build 300,000 new homes between now and 2029 under its current strategy.

Like the rest of the UK, Scotland — which is Springfield Properties’ target market — suffers from a chronic homes shortage that will take years to soothe. Government statistics showed new home starts north of the border fell 17% in the 12 months to last June, to the lowest level since the 1980s.

Given uncertainty over interest rates, there is peril in buying these shares in the near term. But recent signals from the Bank of England (BoE) over rate cuts are encouraging, leading me to believe homebuyer interest could keep improving. Mortgage product wars are also intensifying in a boost to peoples’ afforability.

Springfield is already benefitting from the BoE’s rate-cutting cycle that started last summer. Its latest trading statement revealed “an increased number of private housing reservations” between June and November from a year earlier. Selling prices have also remained robust across its portfolio.

With an undemanding price-to-earnings (P/E) ratio of 12.3 times, I think Springfield Properties could be a great way to consider capitalising on a fresh housing boom.