Is there a way to buy raw oil today and sell it in 1 year time?

Unless you have the storage and transportation facilities for it, or can come up with the money needed to rent or build those, no -- or not in any significant quantity.

Buying oil futures is essentially an on-paper version of the same bet. Futures prices are already taking into account both expectations about price changes and the fact that there's cash tied up until they come due, but storage costs also adjust to follow those expectations.

You can buy the exchange traded fund ETF WTI Crude Oil (CRUD), amongst other ETF products.

http://funds.ft.com/uk/Tearsheet/Summary?s=CRUD:LSE:USD

Note these funds do not 'jump' when the crude oil futures contracts are in contango (e.g. June contract is priced higher than May) and the futures roll-over, as they do monthly. When this happens the ETF continues with no movement. Currently May is $52.85 and June is $54.15 (so in contango). LSE:CRUD is $13.40 and if the crude oil futures rolled-over it would carry straight on at that value. For this reason one should be cautious buying and holding LSE:CRUD longterm.

There are many ways of investing either directly or indirectly in oil:

1. There are commodities brokers that will sell you oil by the barrel and store it for you but the minimum lot size is likely to be large and storage costs may destroy any gains that you make.
2. In the short run you can trade in oil CFDs (contracts for difference) but these are more appropriate for trading in short term movements as they are traded on margin and are very sensitive to small movements in the price.
3. You can trade in futures on the price of oil. These are contracts to buy oil from you in the future at a price fixed now. These can be OTC (over the counter) or exchange traded, exchange traded futures can be bought or sold as you wish but have fixed maturity dates. Being derivatives these are again very risky instruments and, unless you can get 1 year maturity futures (that will likely have to be OTC) you will have to remember to rollover the futures at maturity or risk brokers asking you to hand over barrels of oil.
4. Oil futures ETFs (exchange traded funds) do most of the futures trading work for you and will tend to follow the price of oil quite closely but bear in mind that they are speculative and may have a higher risk profile than just following the oil price (this will be detailed in their fund information). Due to trading in multiple maturity dated futures there will be some reduction in risk from diversification too.
5. Most oil extraction and processing firms' stock prices follow the general direction of the price of oil but benefit from some diversification and many will pay a dividend that will increase your total return.
6. There are also oil industry ETFs and hedge funds that will hold a diversified portfolio of oil industry stocks and options. They will be less closely pegged to the price of oil but will have the benefits of reduced risk and increased total returns from dividends and alpha/beta maximizing active management (for actively managed funds).

all of these options are ways to invest in an expected change in the price of oil at various degrees of directness and risk profiles. Investing in derivative or derivative-like products such as futures and CFDs is very risky and requires a good degree of sophisticated knowledge to manage.

The reason the oil price is low today is because demand is low, production cannot be reduced easily, and people have no space to store oil.

So you won’t be able to buy oil today cheap and sell it in a year for lots of money unless you have the ability to store it. Nobody will be willing to sell you oil cheaply without you physically taking it away.