Most likely, the options cost you nothing. What the company is saying is that at a later time, you are allowed to buy a certain number of shares of the company at 4/$1. If, at that time, the stock is $5, then you can turn right around and sell it on the open market, and make money. On the other hand, if the stock is 0.24, then your options are worthless.
How much the option is worth depends on the total number of shares issued. If there are 10,000 shares outstanding, and you are allowed to buy 100, then that's 1% of the company. Pretty good, if it turns out to be the next Microsoft or Google. If there are 50 million shares, then that's not much.
An initial public offering of a stock is typically at $5 or more. Are you VERY SURE that the company is going public this year? These are hard times, and a startup has to be doing well to go public. Personally, I would be very surprised to see a new solar company go public in the coming year.
If I actually had to pay money to buy the options, now, I would be doubly suspicious of whether the company is actually going public. Maybe they're just trying to raise money (although, I don't know how much they could get from you).
If you have a wealthy and successful relative, I would go to them with the particulars of the deal, and ask them what they would do. Don't trust Y!A for major financial decisions (not even me!)