Is there any difference in impact of adding a set of links as a block in footer vs keeping them as a block in the right or left hand side navigation of the site?
The straight answer is there is no direct impact on SEO ranking when it comes to placing a set of links on top navigation vs footer links.
Instead of thinking about placing set of links on left, right or footer. You should think about better site structure which will be useful for the user.
A good website structure tends to rank better.
The general rule is to place important links in top navigation or footer.
Placing links on left or right is also useful depending on the situation.
Conclusion: Create a website structure which will be useful for the user rather than thinking about SEO ranking.